更多"The fact that mothers in some speci"的相关试题:
[填空题]Animals can not survive some catastrophic events such as starvation, disease, or competition from other species.
[单项选择]Despite the fact that the life span of animals is conveniently divided into separate stages, including the prenatal, adolescent, and senescent, these periods are not truly______.
A. co-dependent
B. reflexive
C. distinct
D. coterminous
E. continuous
[填空题]
Some animals sleep in wintertime
because the weather can be very cold and it is difficult for them to find food.
They can sleep for a long time (from autumn to spring). This kind of winter
sleep is called "hibernation".
If an animal moves about a lot,
it needs food. Hibernating animals do not need to eat much because they are not
moving about. Their hearts beat very slowly and they also breathe slowly. They
find a place that is sheltered from bad weather and they are out of danger.
Their body fat keeps them live and warm.
Some animals, such as
bears, may wake up from their hibernation on warm winter days and then quickly
go back to sleep again when they see the snow is still thick on the ground. When
the weather becomes warmer in spring, the animals wake up for
food. |
Why do some animals sleep in wintertime [A] Bec
[单项选择]Some animals apparently can resist cancer by strengthening their immune system in preparation for winter, Johns Hopkins researchers said on Wednesday.
The scientists said their study is the first to show that the central nervous system, reacting to environmental changes, may spark changes in the body’s immune system that control the growth of tumors.
They said if that is the ease, a better understanding of how the process works eventually could lead to new cancer treatments.
Dr. Randy Nelson, an associate professor of psychology at Hopkins, stressed at a meeting of the Society of Neuroscience that further study would be needed to confirm a connection between the length of the day, the animals’ immune system and cancer. More work also would be needed to show that the findings could be applied to human cancer.
Dr. Faye Austin, an immunologist with the National Cancer Institute in Bethesda, said: "It’s a very intriguing observation that the length of exposure t
A. the findings of animals’ resistance to cancer can be applied to human cancer treatments
B. the length of exposure to light can affect the growth of a tumor
C. there is a relation between the length of the day, the animals’ immune system and cancer
D. there is a new approach for studying the function of central nervous system in the body’s immune system
[多项选择]Definition: Optimal forage means some animals try to waste as little energy as possible to obtain food
[单项选择]People are living longer than ever, but for some reason, women are living longer than men. A baby boy born in the United States in 2003 can expect to live to be about 73, a baby girl, about 79. This is indeed a wide gap, and no one really knows why it exists. The greater longevity (长寿) of women, however, has been known for centuries. It was, for example, described in the seventeenth century. However, the difference was smaller then—the gap is growing.
A number of reasons have been proposed to account for the differences. The gap is greatest in industrialized societies, so it has been suggested that women are less susceptible to work strains that may raise the risk of heart disease and alcoholism. Sociologists also tell us that women are encouraged to be Jess adventurous than men (and this may be why they are more careful drivers, involved in fewer accidents).
Even smoking has been implicated in the age discrepancy. It was once suggested that working women are more likely to s
A. Men’s lifespan remains almost unchanged.
B. Researchers have found the causes of the age gap.
C. The more advanced a society, the greater the age gap.
D. The age gap was noticed only recently.
