更多"Definition: Optimal forage means so"的相关试题:
[填空题]Animals can not survive some catastrophic events such as starvation, disease, or competition from other species.
[填空题]
Price discrimination means charging some buyers more than others for ______ product or service.
[填空题]Some Americans try to make themselves feel less guilty by attributing the poverty of the working people to______.
[单项选择]Some educator try to put students of similar abilities into the same class because they believe this kind of ______ grouping is advisable.
A. homogeneous
B. instantaneous
C. spontaneous
D. anonymous
[单项选择]Some educators try to put students of similar abilities into the same class because they believe this kind of ______ grouping is advisable.
A. homogeneous
B. instantaneous
C. spontaneous
D. anonymous
[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
[单项选择]
Animals are divided into many groups. Some groups of animals include the, insects, fish, amphibians, reptiles, birds and mammals.
Insects are small animals that have six (21) legs and three body parts (the (22) , the thorax, and the abdomen). Many insects can fly; flying insects have one or two (23) of wings. Some flying insects include butterflies, moths, dragonflies, flies, and mosquitoes. Some (24) insects include springtails, fleas, and lice.
Fish are swimming animals that have scales and fins. Fish (25) oxygen that is dissolved in the water using gills. Most fish have bony skeletons, but some, (26) sharks and rays, have only cartilage.
Amphibians are animals that (27) their life in the water, breathing with gills. As they grow, they breathe air using lungs, and many (28) the land. Some amphibians include frogs, toads, salamanders, and newts.
Reptiles are cold-blooded animals (29)
A. babies
B. lives
C. eggs
D. moth
