Why do some people require bifocals (or even trifocals) as they age?​

Answers

Answer 1

Answer:

Explanation:

People have to wear bifocals most commonly because of a condition called presbyopia. This condition occurs naturally. It causes difficulties in the eye’s focusing abilities. Bifocals work to help the eyes focus more clearly, which is why people have to get them.


Related Questions

Mechanical weathering is commonly the result of all of the following except _____.
wind
plant disturbances
gravity
humans
ice
animal disturbances
running water
chemical reactions

Answers

Answer:

The diagram represents the process of enlarging a rectangle using a scale factor of 3. The width of the original rectangle must be:

9 in.

11 in.

12 in.

17 in.

Explanation:

write a paragraph that explains what the causes of Long term climate cycles are. Give examples

Answers

Explanation:

Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions.

Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change:

North America: Decreasing snowpack in the western mountains; 5-20 percent increase in yields of rain-fed agriculture in some regions; increased frequency, intensity and duration of heat waves in cities that currently experience them.

Latin America: Gradual replacement of tropical forest by savannah in eastern Amazonia; risk of significant biodiversity loss through species extinction in many tropical areas; significant changes in water availability for human consumption, agriculture and energy generation.

Europe: Increased risk of inland flash floods; more frequent coastal flooding and increased erosion from storms and sea level rise; glacial retreat in mountainous areas; reduced snow cover and winter tourism; extensive species losses; reductions of crop productivity in southern Europe.

Africa: By 2020, between 75 and 250 million people are projected to be exposed to increased water stress; yields from rain-fed agriculture could be reduced by up to 50 percent in some regions by 2020; agricultural production, including access to food, may be severely compromised.

Asia: Freshwater availability projected to decrease in Central, South, East and Southeast Asia by the 2050s; coastal areas will be at risk due to increased flooding; death rate from disease associated with floods and droughts expected to rise in some regions

15. Suppose a human blood cell containing a 0.9 percent solute concentration were put into a container of 30 percent solute solution. Would the blood cell get bigger or smaller? Why? In your explanation, you must tell me which area has the hypotonic solution (inside the blood cell or outside the blood cell), which area has the hypertonic solution (inside the blood cell or outside the blood cell), and which direction the water would be moving (into the cell or out of the cell).

Answers

Answer:

Smaller

Explanation:

The human blood cell has a smaller percentage of solute concentration than the solution it was placed into. This means that the cell is hypotonic in comparison to the solution, and the solution is hypertonic compared to the cell. When a cell is placed in a hypertonic solution it undergoes crenation, meaning it shrivels up. Water moves from the lower solute concentration to the higher solute concentration. The water inside the cell moves outside to the hypertonic solution. This causes the cell to become smaller.

40. The state of matter with definite shape and definite volume
A. Gas
B. Liquid
C. Solid

Answers

Answer:

C. Solid

Explanation:

Gas has no definite shape or volume, and liquid has no definite shape. Hope this helps, best of luck!

Answer:

solid

Explanation:

liquid flow everywhere

gas blow in water

but solid is in fix shape

explain how incomplete dominance differs from co-dominance

Answers

Answer:

Incomplete dominance is when the phenotypes of the two parents blend together to create a new phenotype for their offspring.

An example is a white flower and a red flower producing pink flowers. Codominance is when the two parent phenotypes are expressed together in the offspring

Explanation:

good luck

Can someone do this lab for me?

I don't have the materials or time. Hopefully, someone has done this before so they can give me some general results and observations. Thanks! :)

Answers

i saw someone with that hold ok lemme try to find it

Explain the importance of using engine powered pump for irrigation works.​

Answers

Answer and Explanation:

Engine irrigation pumps are used to propel water into the irrigation channels, providing full water supply to agricultural crops. The use of the engine pump has advantages and disadvantages. Among the advantages, we can present the simplicity of operation of these pumps, being easily operated efficiently. They also save energy and are essential for irrigation with more viscous liquids, when necessary. This feature is the main reason for using this type of pump.

Among the disadvantages we can say that these pumps have a slower and less accurate work.

Which is NOT a benefit of xenophyophores in a habitat?
1 They maintain benthic biodiversity.
2 They increase populations of isopods, mollusks, and crustaceans.
3 They churn up sediments that build up on the ocean floor.
4 They convert salt and iron into energy and nutrients.

Answers

The correct answer is 4. They convert salt and iron into energy and nutrients.

Explanation

Xenophiophores are large single-celled organisms generally found deep in the deep sea. They are characterized by being very delicate organisms, which makes it difficult for scientists who intend to study them since they are easily damaged by manipulation. However, in the studies that have been carried out on these organisms, it has been found that they are irreplaceable agents in the sediment deposition process and the maintenance of the biological diversity of benthic organisms. Also, it has been shown that in the areas where these organisms are found there are three to four times more benthic crustaceans, echinoderms, and mollusks than the equivalent areas not inhabited by these organisms. On the other hand, none of these studies has proven that They convert salt and iron into energy and nutrients. Therefore, the correct answer is 4. They convert salt and iron into energy and nutrients.

What part do humans play in gene flow?

Answers

Answer:

Humans reproduce and pass on their genes to their offspring.

What pattern of inheritance is represented punnet square

Answers

Answer:

Autosomal Dominant Inheritance

Explanation:

Incomplete Dominance

the law of conservation of mass means that n an isolated system matter cannot be_______

Answers

Answer:

Matter cannot be created nor destoyed

2. A certain recessive, lethal gene is carried on the X chromosome. (Lethal genes are those that result in death.) A man marries a woman who is hybrid for this gene. What sex ratio would be expected among the living children of this couple?
%Male
%Female​
Please help me im stuck!

Answers

The surviving children would be 66.7% female and 33.3% male. Of the female children, 50% would be expected to be carriers of this gene (like their mother)
| Xg | X
—————-
X | XXg | XX
—————-
Y | XgY | XY

Pretty ugly, but the best punnet square I can do without a link. The offspring with the “g” are those that carry the lethal gene. The male child that carries it will die, but since it is recessive, the female child will live but will be a carrier for this gene. I hope this helps.

What are the two main ways bacteria cause illness?
A. By releasing toxins that poison your cells
B. By using your cells to make copies of themselves
C. By changing the genetic material inside your cells
D. By breaking down your cells for nutrients

Answers

Answer:

A. By releasing toxins that poison your cells

B. By using your cells to make copies of themselves

Explanation:

Within the body, bacteria can divide (multiply) and kill host cells by disrupting their normal functioning. Moreover, bacteria secrete toxins that are able to destroy host cells' metabolic machinery.  For instance, many bacteria synthesize exoenzymes and interferons that disrupt and destroy host cells. Bacterial toxins can be synthesized internally in order to develop sensitivity through antigenic properties.

How many kidneys are in the average
adult human?

Answers

Answer:

Two kidneys

Explanation:

Most people have two kidneys, however, it is possible to live a healthy and active life with only one functioning kidney.

PLEASE HELP !! ILL GIVE 40 POINTS ; PLUS BRAINLIEST !! DONT SKIP ANSWER.

Answers

Answer:

I think it is B

Explanation:

Im sorry if i am wrong

An isometric exercise is one in which the joint angle does not change during the application of muscle force. For instance, you can join your hands together, pushing down with one hand and pushing up with the other. In each arm, the muscles that provide the force are connected to the bones of the arm by tendons. If you increase the forces but keep the angles the same, the muscles will still contract. Explain how this is possible.

Answers

An isometric exercise is a form of exercise involving the static contraction of a muscle without any visible movement in the angle of the joint.

I I am really really confused about these two questions does anybody know the answer to both of them

Answers

Answer:

1) Topographic maps show contours, elevation, forest cover, marsh, pipelines, power transmission lines, buildings and various types of boundary lines such as international, provincial and administrative, and many others. (Answer: Elevation)

2) Contour line, a line on a map representing an imaginary line on the land surface, all points of which are at the same elevation above a datum plane, usually mean sea level. The diagram illustrates how contour lines show relief by joining points of equal elevation. (Answer: Contour Line)

Which one ??????????????

Answers

Answer:

It allows genetic variation

Explanation:

According to the law of conservation of energy, what can happen to the total
energy of a system?
A. The total energy must remain the same, but energy can change
forms and be transferred within the system.
B. Energy must be transferred out of a system if energy is transferred
into the system so that they total energy of the system stays the
same.
C. The total energy can decrease when energy is lost due to energy
transformation within the system.
D. The total energy can increase if energy is transferred into the
system from surroundings.
SUBMIT

Answers

Answer:

the total energy must remain the same,but energy can change forms and be transferred within the system

What is the Society of American Foresters?
A union
A business
A government agency
A professional organization

Answers

The answer would be D

If several species of carnivores are removed from an ecosystem, the most likely effect on the ecosystem will be an increase in stability among populations.

Answers

i think so since carnivours could lead to effects on ecosystem such as the number or behaviour of their herbivore prey

what is another name for environmental science? ​

Answers

Ecology, Environmental monitoring

1. Which process returns water to Earth?
photosynthesis
nitrification
fingecipitation
evaporation
Which is it?

Answers

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Answer: Evaporation

I hope this helped!

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- Zack Slocum

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Evaporation •••••••••

When a meteor crosses the sky, the light given off is caused by
O Friction
Gravity
O Solar Winds
O Erosion

Answers

Answer:

the answer is EROSION, I Believe

Answer:

Friction

Explanation:

Why is stem cell research important within the field of medicine?

Answers

Researchers and doctors hope stem cell studies can help to increase understanding of how diseases occur, and to better understand how diseases and conditions develop.

Moving substances from a lower concentration to a higher concentration requires _____. passive diffusion facilitated diffusion active transport pinocytosis

Answers

Answer:

Active Transport <3

Explanation:

Which of the following factors decrease biodiversity? (Choose all that apply)
a. habitat destruction
b. unpredictable precipitation
c. warm temperatures
d. freezing temperatures

Answers

Answer:

habitat destruction, unpredictable precipitation, and freeing temperatures.

Explanation:

i took the quiz

The destruction of the habitat, unpredictable precipitation, and freezing temperatures decreases biodiversity. Thus, options a, b, and d are correct.

What is biodiversity?

Biodiversity is the variety of life that sustains on earth and lives in a particular habitat. The biodiversity can be measured based on the ecosystem, species, and genetics. It comprises the ecological and evolutionary process.

The destruction of the habitat of a species can lead to a decrease in biodiversity as it affects the ecosystem and the ecological pyramid as a whole and will affect the population of the species.

The unpredictable precipitation can affect the species and the habitat as it may lead to floods that will destroy the habitat hence resulting in the loss of species.

Similarly, the decrease in temperature will affect many species as they will not be able to cope with low temperature resulting in their death.

 

Therefore, the unpredictable precipitation, freezing temperature, and destruction of habitat lead to a decrease in biodiversity.

Learn more about biodiversity here:

https://brainly.com/question/13073382

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which fish is exotic in among these common carp or mori or thaila?​

Answers

Answer:

common carp

Explanation:

Given that Exotic fishes are a type of fishes that being raised in an environment that is not native to them. Usually, exotic fishes are known for surviving easily in a country that is not originally their own.

Among the available options, COMMON CARP is a type of fish that is known for its exotic nature. So far, it has been introduced to other continents and countries other than their country of origin.

They easily reproduced and multiply, thereby easily adapt and populate their new environment.

barometers modified to measure the height above the sea level are called​

Answers

Answer:

When a barometer is supplied with a nonlinear calibration so as to indicate altitude, the instrument is called a pressure altimeter or barometric altimete

Explanation:

Altimeters

An altimeter is a device that measures altitude, the distance of a point above sea level. Altimeters are important navigation instruments for aircraft and spacecraft pilots who monitor their height above the Earth's surface.

Take any two words and connect them to form a sentence about photosynthesis.
____________ and ___________ go together because_______________________.
Terms:
Calvin Cycle
Carbon Dioxide
Chlorophyll
Chloroplast
Glucose
Leaf
Light
Light Dependent Reaction
Light Independent Reaction
Oxygen
Photosynthesis
Pores
Product
Reactant
Root
Starch
Sun
Water

Answers

Answer:

Solution:

plant's takes carbon dioxide ,water ,sunlight,and minerals and produce glucose and excrete out oxygen:

Take any two words and connect them to form a sentence about photosynthesis.
PRODUCT and REACTANT go together because any reactants in a chemical equation will result in a product of the reactants.
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Solve for x A.3/4 B.52/7 C.17D. 52/3 Which of the following statements about slang is true? O A. Use slang frequently because it will provide evidence of popular words at the time of your writing. O B. Slang often communicates your point correctly, but it's not appropriate for formal writing. O C. Slang represents passing fads, so it should never be used in any type of writing. O D. You don't need to take your audience or purpose into account when using slang this please I fricking can't understand the question............. A fair coin is tossed 6 times. What is the probability of getting H,H,T,T,H,T in that order? Historical Context (Why was the US interested in China? What happened in China before the U.S. government arrived? What are some ways Shackleton failed a s a leader? What factors influenced Trumans decision to use atomic weapons against Japan? Complete the table (100 points) a customer complains about the food, saying it does not suit his taste. what will you do? please help will mark brainlist What are some exceptions to Mendel's principles? ***15 POINTS***Name one political and one social issue that occurred as a result of Louisiana becoming a state. A Soledad le gusta ________ el Da de las Madres en su casa. bailar celebrar hablar mirar 5. Find the value of x. Enter the numeric value only. Round your answer to 10 pointthe nearest hundredth. The Great Depression was a result ofA. WarB. Stock market crashC. Change in governmentD. Unhappy peopleSUBMI What is the volume of the figure below, which is composed of two cubes with side lengths of 6 units?A. 216 cubic units B. 360 cubic units C. 432 cubic units D. 36 cubic units How does being passionate affect others can someone please write these words in a sentence catamount,cat-a-mountain,mountain lion,panther,puma. 1) 3n + 5n +7A) quadratic monomialB) cubic binomialC) constant trinomialD) quadratic trinomial What is the answer please help no links no links