6. The title of this text is "Why Do Cave Fish Lose Their Eyes?" Why might the author have written the title as a question?
A. to encourage readers to answer the question on their own before they read the article
B. to prepare readers for a discussion of possible answers to this question in the article
C. to criticize scientists for not having reached a definite answer about why cave fishes
lose their eyes
D. to praise scientists for the effort they have put into understanding the cause of
blindness in cave fishes

Based on their location in the atmosphere, the layers are able to have their own special characteristics. for example, most weather occurs in the troposphere. what occurs in each of the other layers? (site 1)

Mike was adopted, and his biological family history is unknown. although he is healthy, he would like some understanding of his genetic makeup, including potential health risks and genes that he could pass on to his children. mike has heard about commercial laboratories that can compare segments of your dna to those of people with common hereditary diseases in order to give you some idea of how susceptible you are to the diseases. the results of these types of tests are highly inconclusive. if mike's dna showed that he shares similarities in a segment of dna with people who have a given disease, his chances of developing that disease or passing it on to his children may be slightly elevated, but they are not 100 percent. these tests can cost more than $2,500 and are not covered by many insurance companies. do you think that mike should undergo the genetic tests? explain your answer. what are the potential pros and cons of having such tests done? describe how the availability of these genetic tests might affect the frequency of genetic diseases in individuals and populations.

What is hydroelectric power produced by?