[填空题]Infrared radiation can produce heat ______.

[单项选择]Why can’t people on earth be harmed by radiation
A. Because men on the Earth are protected by the atmosphere.
B. Because radiation only has short-term effects on men on the Earth.
C. Because there is a great distance between the Earth and the radiation areas.
D. Because the Van Allen Belts absorb all radiation.

[单项选择]A. A technology to produce a substance that can be made into sugar.
B. A technology to load garbage into a huge pressure cooker.
C. A technology to turn plant wastes and other garbage into fuel.
D. A technology to produce automobiles operating on high-ethanol fuel.

[简答题]Why can interviews produce more information than questionnaires

[填空题]The lnductrack Ⅱ design can produce a very strong magnetic field even when the train runs more slowly by ______.

[填空题]Continuing stress can make people’s bodies produce more cortisol and insulin.

[单项选择]

Green plants can produce their own food. They use substances in the environment. This process is known as photosynthesis. In contrast, all animals including humans, get their food either directly from plants or indirectly by eating animals which have eaten plants. So animals take in a wider range of foods than plants.
Plants are generally stationary. They do not have the power of locomotion. Animals, on the other hand, can usually move around. Therefore, plants appear to be less sensitive than animals although they respond in some ways to light, heat, physical contact and other stimuli.
In external appearance plants are usually green. They grow in a branching fashion at their extremities. Their growth continues throughout their lives. Animals, however, are very diverse in their external appearance. Their growth pattern is not limited to their extremities but is evenly distributed. Growth occurs in a definite period of time.
The most basic difference betwee
A. Plants produce their own food but animals don’t.
B. Plant cells have a wall which is non-living in chemical nature but animal cells haven’t.
C. Plants are green but animals aren’t.
D. Plants can’t move but animals can.

[单项选择]

Some desert animals can survive the summer heat and dryness because they are very unusual. The camel, for example, can experience and bear an increase in the temperature of its body and its blood of 9°C without anything bad happening to it. In addition, it can drink a lot of water at one time; then store enough water in parts of its body to supply its needs for two weeks or more. The kangaroo rat, on the other hand, gets all the water it needs from water that it produces when it breathes. However, most animals need to maintain a fairly constant body temperature, and will die if it rises more than 5°C. Therefore, they need to find some way to stay away from the heat of the summer sun. Nor can many animals either store or produce water in their bodies, as the camel and kangaroo rat can. So they must find ways to keep their bodies from losing water because of the heat. Because very few desert animals can survive the high temperature of a typical summer’s day, most of t
A. it can produce water through breathing
B. it can store water in parts of its body
C. it can maintain different body temperatures
D. it can drink a 10t of water at a time