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问题 选择题

翻阅科普资料时，小明发现20世纪90年代，科学家在宇宙深处发现了一种由氢元素组成的新物质，其符合为H3．下列有关该物质说法中正确的是（　　）

A．该物质是氢气

B．该物质属于单质

C．该物质属于氢元素的化合物

D．该物质与氢气充分混合后属于纯净物

答案

A、这种物质的化学式是H3，不是氢气．故A错误；

B、H3是由氢元素组成的纯净物，属于单质．故B正确；

C、由B分析可知C说法错误．故C错误；

D、H3与H2是不同的物质，因此两者混在一起属于混合物．故D错误．

故选B．

单项选择题

正常心电图心房激动产生的波是()。

A．P波

B．Q波

C．R波

D．T波

E．U波
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单项选择题

Research on animal intelligence always makes me wonder just how smart humans are. (91) the fruitfly experiments described in Carl Zimmer’s piece in the Science Times on Tuesday. Fruit flies who were taught to be smarter than the average fruit fly (92) to live shorter lives. This suggests that (93) bulbs burn longer, that there is an (94) in not being too terrifically bright.
Intelligence, it (95) , is a high-priced option. It takes more upkeep, burns more fuel and is slow (96) the starting line because it depends on learning—a gradual (97) —instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (98) .
Is there an adaptive value to (99) intelligence That’s the question behind this new research. I like it. Instead of casting a wistful glance (100) at all the species we’ve left in the dust I.Q. wise, it implicitly asks what the real (101) of our own intelligence might be. This is (102) the mind of every animal I’ve ever met.
Research on animal intelligence also makes me wonder what experiments animals would (103) on humans if they had the chance. Every cat with an owner, (104) , is running a small-scale study in operant conditioning, we believe that (105) animals ran the labs, they would test us to (106) the limits of our patience, our faithfulness, our memory for terrain. They would try to decide what intelligence in humans is really (107) , not merely how much of it there is. (108) , they would hope to study a (109) question. Are humans actually aware of the world they live in (110) the results are inconclusive.

A．incredible

B．spontaneous

C．inevitable

D．gradual
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