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问题 单项选择题

小明的爸爸在高山上工作，那里的气温白天和夜晚相差很大，他的手表由于受气温的影响走得不正常，白天快分钟，夜里慢分钟。他10月1日对准时间，问到哪一天手表正好快5分钟（）

A．10月15日

B．10月23日

C．10月28日

D．11月1日

答案

参考答案：C

解析：

这块手表一整天(24小时)快，则要快4.5分钟需4.5，再加一个白天正好快分钟，因此到10月28日，手表正好快5分钟。故选C。

单项选择题

Most plants can make their own food from sunlight, (1) some have discovered that stealing is an easier way to live. Thousands of plant species get by (2) photosynthesizing, and over 400 of these species seem to live by pilfering sugars from an underground (3) of fungi(真菌). But in (4) a handful of these plants has this modus operandi been traced to a relatively obscure fungus. To find out how (5) are (6) , mycologist Martin Bidartondo of the University of California at Berkeley and his team looked in their roots. What they found were (7) of a common type of fungus, so (8) that it is found in nearly 70 percent of all plants. The presence of this common fungus in these plants not only (9) at how they survive, says Bidartondo, but also suggests that many ordinary plants might prosper from a little looting, too.

Plants have (10) relations to get what they need to survive. Normal, (11) plants can make their own carbohydrates through photosynthesis, but they still need minerals. Most plants have (12) a symbiotic relationship with a (13) network of what are called my corrhizal fungi, which lies beneath the forest (14) . The fungi help green plants absorb minerals through their roots, and (15) , the plants normally (16) the fungi with sugars, or carbon with a number of plants sharing the same fungal web, it was perhaps (17) that a few cheaters—dubbed epiparasites—would evolve to beat the system. (18) , these plants reversed the flow of carbon, (19) it into their roots from the fungi (20) releasing it as "payment.\

3（）

A.realm

B.net

C.relation

D.web
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单项选择题

要按规定时间检查联动机万向轴连接法兰盘螺栓紧固情况，扭紧时要按（）顺序扭紧。

A.对角

B.顺时针

C.逆时针

D.间隔
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