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问题 选择题

（2011年甘肃兰州，12题）下列厨房用具，在空气中最易锈蚀的是（ ）

A．铁锅

B．纯铜把手

C．铝壶

D．不锈钢汤勺

答案

答案：A

本题考查的是金属锈蚀的条件及其防护。

A、铁与氧气、水等反应生成的铁锈很疏松，不能阻碍里层的铁继续与氧气、水等反应，铁制锅因此在空气中最易锈蚀，故A符合；

B、铜的金属活动性弱，在常温下不与水和氧气反应，不易锈蚀，故B不符合；

C、铝在空气中与氧气反应，其表面会生成一层致密的氧化铝薄膜（Al2O3），能覆盖在铝表面，从而保护里层的铝不再与氧气反应，因此铝制水壶在空气中不易锈蚀，故C不符合；

D、不锈钢中还含有铬、镍等，使得不锈钢不仅比纯铁硬，而且其抗锈蚀性能也比纯铁好得多，故D不符合。故选A

单项选择题

正常人尿量白天与夜间之比约为（）。

A.1～2：1

B.2～3：1

C.3～4：1

D.4～5：1

E.5～6：1
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单项选择题

Research on animal intelligence always makes us wonder just how smart humans are. (1) the fruit-fly experiments described by Carl Zimmer in the Science Times. Fruit flies who were taught to be smarter than the average fruit fly (2) to live shorter lives. This suggests that (3) bulbs burn longer, that there is a(n) (4) in not being too bright.

Intelligence, it (5) , is a high-priced option. It takes more upkeep, burns more fuel and is slow (6) the starting line because it depends on learning — a(n) (7) process — instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (8) .

Is there an adaptive value to (9) intelligence That’s the question behind this new research. Instead of casting a wistful glance (10) at all the species we’ve left in the dust I.Q.-wise, it implicitly asks what the real (11) of our own intelligence might be. This is (12) the mind of every animal we’ve ever met.

Research on animal intelligence also makes us wonder what experiments animals would (13) on humans if they had the chance. Every cat with an owner, (14) , is running a small-scale study in operant conditioning. We believe that (15) animals ran the labs, they would test us to (16) the limits of our patience, our faithfulness, our memory for locations. They would try to decide what intelligence in humans is really (17) , not merely how much of it there is. (18) , they would hope to study a(n) (19) question: Are humans actually aware of the world they live in (20) the results are inconclusive.

5（）

A. insists on

B. sums up

C. turns out

D. puts forward
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