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问题 填空题

长度测量的常用工具是______，使用前应注意观察其零刻度是否磨损及______和______．

答案

长度测量的常用工具是刻度尺，使用前应注意观察其零刻度是否磨损及量程和分度值．

故答案为：刻度尺；量程；分度值．

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.\

9（）

A.shows

B.denotes

C.indicates

D.hints
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选择题

公元前445年，罗马废除贵族与平民不能通婚的旧法；公元前367年，又以法律形式授予平民与贵族分享公有土地的平等权利。罗马制定上述法律的主要目的是[ ]

A．完善法律体系

B．稳定社会秩序

C．保障平民利益

D．维护帝国统治
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