[单项选择]　　One reason why a sheep, a less well-understood experimental subject than the laboratory mouse, should have proved easier to clone may stem from differences in the initial stages of the two species’’ embryonic development. After reaching maturity in the ovary of the mother, the unfertilized eggs of all mammals accumulate a supply of proteins, and the means of producing fresh protein. In this way, the mammalian egg brings with it a larder for the embryo to make use of until its own genes activate and supply this requirement themselves. The sheep embryo disposes of its store properly and need not depend on its own genes until the sixteen-cell stage, four cell divisions successive to fertilization, while in contrast, the mouse embryo commences this process more precociously, becoming reliant on the activity of its own genes after just the first division when the fertilized egg becomes two cells. Therefore, a foreign nucleus introduced into a sheep egg exploits a respite in its host’’s bi
A. advancing an argument against human cloning based on evidence from cloning experiments performed on lower life forms
B. measuring the technical and ethical limitations of the embryonic cloning process in mammals
C. refuting arguments against human cloning through the use of hard scientific evidence
D. illuminating the critical ethical distinctions in process between human cloning and sheep cloning
E. describing how the ethical issues in the quest for human cloning have given rise to new models of embryonic development

[单项选择]　　One reason why a sheep, a less well-understood experimental subject than the laboratory mouse, should have proved easier to clone may stem from differences in the initial stages of the two species’’ embryonic development. After reaching maturity in the ovary of the mother, the unfertilized eggs of all mammals accumulate a supply of proteins, and the means of producing fresh protein. In this way, the mammalian egg brings with it a larder for the embryo to make use of until its own genes activate and supply this requirement themselves. The sheep embryo disposes of its store properly and need not depend on its own genes until the sixteen-cell stage, four cell divisions successive to fertilization, while in contrast, the mouse embryo commences this process more precociously, becoming reliant on the activity of its own genes after just the first division when the fertilized egg becomes two cells. Therefore, a foreign nucleus introduced into a sheep egg exploits a respite in its host’’s bi
A. The sheep was chosen as an ideal subject because of its genetic development, not for its precedence as a research subject.
B. The human embryo comes to rely upon its own genetic code at an earlier stage of development than the mice embryo.
C. The unfertilized sheep egg acquires a limitless supply of protein from the mother’’ s ovary.
D. The earlier the foreign nucleus assumes genetic control of the embryo, the more successful it will likely be.
E. The foreign nucleus transplanted to an embryo may be consider "older" than the nucleus it replaced.

[单项选择]

Passage One

Why does the speaker mention the architect Wright（）
A. Because many architects studied with Wright.
B. Because Wright started the practice of "land-scraping".
C. Because Wright used elements of envelope building.
D. Because most of the houses Wright built were made of stone.

[填空题]Why are distances becoming less

[单项选择]
No one knows exactly why we sleep. But scientists have learned a lot about how we sleep.
When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call it dozing (打盹). Next, you enter into a deeper sleep. Your pulse (脉搏) and breathing become even slower. But you can still be awakened quite easily. If you take a catnap, you probably will not get any further than this stage (阶段) of sleep. If you sleep longer than about twenty minutes, you get into the third one. Your body is very relaxed. It would take a loud noise to wake you up. You may have heard of people who walk in their sleep. No one knows what makes people sleepwalk. But a person can sleepwalk only during stage four. This is the last and deepest kind of sleep. If someone wakes you up, you might feel very uncomfortable and you need a few minutes to get used to being awake. A
A. two
B. three
C. four
D. five

[单项选择]
No one knows exactly why we sleep. But scientists have learned a lot about how we sleep.
When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call it dozing (打盹). Next, you enter into a deeper sleep. Your pulse (脉搏) and breathing become even slower. But you can still be awakened quite easily. If you take a catnap, you probably will not get any further than this stage (阶段) of sleep. If you sleep longer than about twenty minutes, you get into the third one. Your body is very relaxed. It would take a loud noise to wake you up. You may have heard of people who walk in their sleep. No one knows what makes people sleepwalk. But a person can sleepwalk only during stage four. This is the last and deepest kind of sleep. If someone wakes you up, you might feel very uncomfortable and you need a few minutes to get used to being awak
A. two
B. three
C. four
D. five

[单项选择]{{B}}Section B{{/B}}

Why did Tommy Carter go to China for his soybean research
A. China is the only country to grow soybeans.
B. China is the ancestral home of soybeans.
C. China has a long history of growing soybeans.
D. China has different kinds of soybeans.