I'll stay here _____ everyone else comes back.

As if there weren’t enough of them in the world already, scientists have succeeded in cloning flies. The alike fruit flies are the first insects ever cloned, says the Canadian team that created them. The question everyone asks is why anyone would want to clone flies in the first place. She hopes that the insects , which are very easy to experiment with , will help to adjust the cloning process in other animals and even in humans, where the technique is being researched to aid production of therapeutic (治疗的) stem cells.

In cloning, the DNA-containing nucleus of an adult cell is injected into an egg whose own nucleus(细胞核) has been removed. At the moment, the majority of cloned mice, sheep and other animals die before birth. It is thought this is because the adult DNA is not properly ‘reprogrammed’.

Using flies, researchers might discover genes that are important for this reprogramming, and that have matches in other animals. That is because it is relatively easy in flies to knock out the function of a single gene and then attempt cloning with these cells, which will test whether that gene is important. If such genes are confirmed, then in theory cloned mammalian embryos(晶胚) might be grown in selected solutions that change the activity of those genes to improve the technique’s success rate. Although some groups have attempted to clone insects before, Lloyd says this is the first time it has been successful. The team used a slight difference on the standard cloning process: they transferred nuclei taken from embryos rather than fully-grown adult cells. They sucked several nuclei (pl)out of developing fly embryos, and injected them into a fertilized(已受精的) fly egg. From over 800 early attempts, they cloned five adult insects, the group reports in the journal Genetics.

1.The best title of this passage probably is _______.

A．The importance of clone

B．First insects are cloned

C．The disagreement in clone

D．The advantages of clone

2.The scientists cloned flies because________.

   A．there are fewer and fewer flies in the world 

B．flies are easy to find and cheap to use

   C．they can gain some experience before cloning other animals

   D．it is safe to clone flies

3.The failure of most cloned animals is due to _______.

   A．the difference of other animals’ genes

   B．the improper technique of clone

   C．the complex of other animals

   D．the improper rearrange of the adult gene

4.It can be inferred from the last paragraph that ______.

   A．the clone of insects before used grown-up cells

  B．the clone of insects were never experimented before  

C．this time scientists cloned flies successfully and easily

   D．based on this success, other animals will be cloned in large quantities. 

As if there weren’t enough of them in the world already, scientists have succeeded in cloning flies. The alike fruit flies are the first insects ever cloned, says the Canadian team that created them. The question everyone asks is why anyone would want to clone flies in the first place. She hopes that the insects , which are very easy to experiment with , will help to adjust the cloning process in other animals and even in humans, where the technique is being researched to aid production of therapeutic (治疗的) stem cells.

In cloning, the DNA-containing nucleus of an adult cell is injected into an egg whose own nucleus(细胞核) has been removed. At the moment, the majority of cloned mice, sheep and other animals die before birth. It is thought this is because the adult DNA is not properly ‘reprogrammed’.

Using flies, researchers might discover genes that are important for this reprogramming, and that have matches in other animals. That is because it is relatively easy in flies to knock out the function of a single gene and then attempt cloning with these cells, which will test whether that gene is important. If such genes are confirmed, then in theory cloned mammalian embryos(晶胚) might be grown in selected solutions that change the activity of those genes to improve the technique’s success rate. Although some groups have attempted to clone insects before, Lloyd says this is the first time it has been successful. The team used a slight difference on the standard cloning process: they transferred nuclei taken from embryos rather than fully-grown adult cells. They sucked several nuclei (pl)out of developing fly embryos, and injected them into a fertilized(已受精的) fly egg. From over 800 early attempts, they cloned five adult insects, the group reports in the journal Genetics.

1.The best title of this passage probably is _______.

    A．The importance of clone

    B．First insects are cloned

    C．The disagreement in clone

    D．The advantages of clone

2.The scientists cloned flies because________.

   A．there are fewer and fewer flies in the world 

    B．flies are easy to find and cheap to use

   C．they can gain some experience before cloning other animals

    D．it is safe to clone flies

3.The failure of most cloned animals is due to _______.

   A．the difference of other animals’ genes

   B．the improper technique of clone

   C．the complex of other animals

   D．the improper rearrange of the adult gene

4.It can be inferred from the last paragraph that ______.

   A．the clone of insects before used grown-up cells

    B．the clone of insects were never experimented before  

    C．this time scientists cloned flies successfully and easily

   D．based on this success, other animals will be cloned in large quantities.

1.__________

Current research into the human gene system is helping us understand why people have predispositions（易患某病倾向）to certain diseases．Knowing our genetic makeup can help us to judge whether or not we may be stricken by particular illness, such as cancer．Even before birth, we are able to do genetic screenings to determine what a child's genetic disorder will be．Scientists have already isolated and identified the genes responsible for the more than 4,000 genetic diseases that affect human beings．

2.__________

The implications of this knowledge are astonishing. In addition to predicting genetic predisposition towards diseases, gene therapies may provide new treatments or cures for serious diseases．Millions of people already use genetically engineered drugs to treat heart disease, cancer, AIDS, and strokes （中风）. But with the research that is now being conducted, we may find cures to many more diseases．In the near future, genetic experimentation will also allow parents to select the traits of their children. Genetic traits that determine height, weight, eye and hair color will be able to be controlled, and many parents are excited about this potential.

3.__________

Many people, however, are unwilling to accept the possibilities genetic research allowsFor example, one reason some women do not use the largest genetic testing for breast cancer is because they are afraid they will be discriminated against．Another problem is that many people do not want to discover their weakness．What if they learn that they have a disease for which there are no medical cures? How will such knowledge affect their lives? Do people really want to know what they will die of?

4.__________

Many people believe that history has not always shown human decision-making to be bright when it comes to ethical（道德的）choices. Jeremy Rifkin is probably the most well known opponent of genetic engineering. He believes that humans are not responsible enough to experiment with genes and should not “play God” He asks, “Just because it can be done, does that mean it should be done?” He points out that our society will eventually look and act the same if parents select the traits of their children, and he questions the desirability of such a society．

5.．__________

One of the fears expressed about genetic experimentation involves privacy. Already blood sample taken from patients in hospitals have been used for genetic research without the patients’ permission. Most people would agree that one’s health and genetic makeup are private concerns. But if insurance companies gain access to this information, it could have a large impact on insurance coverage or costs; if employers gain access to the information, it could have a large impact on hiring or promotion decisions. The possibilities for discrimination are obvious．