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
参考答案：C
解析：
本题各选项的意思分别是：A．insist on(坚持)；B．sum up(总结)；C．turn out(证明是)；D．put forward(提出)．此题若从语法角度分析，发现无法理解，因为原文出现两组主谓结构，但没有连接词．实标上，这里it引导的主谓结构作为插入语，it是主语复指现象。选项A、选项B和选项D只能以 sb作为主语，唯有turn out可以用“it”作主语。此句译为“事实证明，智力是要付出昂贵代价的选择。”所以选择C。
丘，凹者为壑。