单选题 Imagine an animal that becomes frozen in cold weather. Then, when it gets warmer, the animal simply unfreezes and goes back to its normal life. Although this may sound like something from a science-fiction movie, it is exactly what happens to the wood frog over winter and spring. When winter begins, the frog, which is found throughout much of Canada, buries itself in leaves and dirt. As the ground begins to freeze, so does the frog's body.
Normally, if a living creature is frozen, the cells inside its body are destroyed, leading to death. How, then, does the wood frog survive? The secret lies in the fact that although the water between the cells in the frog's body becomes frozen, the water inside the cells does not freeze. Before the winter begins, the frog stores starch in its body. As the weather gets colder, the drop in temperature causes the frog's body to change this starch into glucose. This glucose, in turn, lowers the temperature at which the liquid inside the frog's cells freezes. As a result, the cells do not freeze even at very low temperatures, allowing the frog to stay alive. Some wood frogs stay in this frozen state—with their hearts stopped completely—for months without harm.
Now researchers are hoping to adapt the wood frog's secret to help them preserve human organs for transplants. Currently, after organs are removed from a donor's body, they are packed in a special liquid and kept very cold. However, they cannot be frozen because the ice would damage the cells in the organs. For this reason, the organs must be used quickly. If doctors had a way to preserve organs longer, they would have more time to find the best matches among people waiting for organ transplants.
There is still a lot about the wood frog that scientists do not understand. They still have to work out, for example, exactly how the frog is able to unfreeze itself and what actually restarts the frog's heart when the weather becomes warmer. What is clear, however, is that lessons learned by studying this tiny creature could be of great benefit to humans in the near future.

单选题 The wood frog is unusual because it ______.

A、 can move about easily on frozen ground
B、 buries itself in leaves and dirt at the start of spring
C、 survives even after its body has become frozen
D、 lives a normal life even in very cold weather

【正确答案】 C

【答案解析】细节题。根据短文开头内容...frozen in cold weather...unfreezes and goes back to its normal life. 以及this may sound...science-fiction movie...wood frog可知wood frog的不寻常之处在于即使它全身都结冰了，它也可以复活。故选C。

单选题 What effect does the glucose produced in the wood frog's body have?

A、 It stops the water in the frog's cells from freezing in cold weather.
B、 It lowers the temperature in the spaces between the frog's cells.
C、 It causes the frog's cells to produce more starch.
D、 It allows the frog's cells to produce more water.

【正确答案】 A

【答案解析】细节题。短文第二段中间指出This glucose, in turn, lowers the temperature at which the liquid inside the frog's cells freezes. 意为这种葡萄糖可以降低wood frog细胞液体结冰的温度。由此可知这种葡萄糖使细胞里的水不会结冰，故选A。

单选题 Researchers are hoping to use the wood frog's secret to allow them to ______.

A、 use transplant organs more quickly
B、 remove organs from a donor more easily
C、 unfreeze transplant organs with chemicals from the frogs
D、 keep transplant organs longer than they can now

【正确答案】 D

【答案解析】细节题。根据短文第三段前半部分help them preserve human organs for transplants和最后If doctors had a way to preserve organs longer，可知选项D正确。

单选题 Which is one thing that scientists would like to find out about the wood frog?

A、 Whether it becomes frozen in the spring.
B、 How its heart starts again when it unfreezes.
C、 Which parts of its body freeze in cold weather.
D、 Why it takes so long to unfreeze at the end of winter.

【正确答案】 B

【答案解析】细节题。作者在最后一段指出...work out...how the frog is able to unfreeze itself and what actually restarts the frog's heart...，由此可知，答案为B。

单选题 Which of the following is true?

A、 The wood frog needs starch in order to stop the cells in its body from dying.
B、 Researchers are trying to find a way to transplant the organs of wood frogs.
C、 Wood frogs use the glucose in their cells to unfreeze their bodies at the end of winter.
D、 Scientists are now using the process that takes place in a wood frog's body to prepare human organs for transplant.

【正确答案】 A

【答案解析】细节题。根据短文第二段对wood frog这种特殊能力的描述以及the frog stores starch in its body和This glucose...lowers the temperature...可知选项A正确，选项C错误；根据短文倒数第二段中researchers are hoping to adapt...help them preserve human organs for transplants，由此可排除B、D。故选A。