题目

写出下列化学方程式。 （1）木炭和氧化铜在高温下反应    （2）用过氧化氢溶液制氧气         （3）将硝酸银溶液滴入氯化钠溶液       答案：C＋2CuO  2Cu＋CO2↑ 2H2O2   2H2O＋O2↑ NaCl＋AgNO3=AgCl↓＋NaNO3Certain animals know without analysis the difference between a number of objects and a smaller number. In his book The Natural History of Selbourne (1786), the naturalist Gilbert White tells how he surreptitiously removed one egg a day from a kind of bird Plover’s nest, and how the mother laid another egg each day to make up for the missing one. He notes that other kinds of birds ignore the loss of a single egg, but if more than one egg has been removed, they will give up their nests. It has also been noted that a certain type of bees always provides five—never four, never six—caterpillars (毛虫) for each of their eggs so that their young have something to eat when the eggs have hatched out. Research has also shown that both mice and pigeons can be taught to distinguish between odd (奇数) and even (偶数) numbers of food pieces. These have led some people to think that creatures can actually count. They also point to dogs that have been taught to respond to questions about numbers with the correct number of barks.Animals respond to quantities only when they are connected to survive as in the case of the eggs, or survive as in the case of food. They can “count” only when the objects are present and only when the numbers involved are small—no more than seven or eight. In lab experiments, animals which are trained to count one kind of objects were unable to count any other type. What interests them are the objects, not the numbers. Animals’ achievements simply are not equal to evidence of counting. They only show the results of clever, careful training.小题1:The author refers to Gilbert’s book in paragraph 1 in order to_______.A．support the idea that animals can countB．show attitudes have changed since 1786C．prove that some animals are aware of quantitiesD．indicate that more research is needed in this field小题2:The author mentions all of the following are aware of quantities in some way EXCEPT _______.A．caterpillarsB．beesC．miceD．plovers小题3:The underlined word “surreptitiously” probably means _______.A．quicklyB．carefullyC．occasionallyD．secretly小题4:Where does this text probably come from?A．A news report.B．A science fiction.C．A park guide.D．A biology magazine.