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问题 填空题

对于基带总线而言，用于检测一个冲突的时间等于任意两个站之间最大传输延迟的（）倍。而对于宽带而言，冲突检测时间为任意两个站之间最大传播延迟的（）倍。

答案

参考答案：二、四

单项选择题

Should we care if over 150 known species of animals have (91) from the earth in the last fifty years Should we be concerned that there are (92) thousands of species whose very existence is (93) endangered—largely because of our activities (94) , after all, is the natural end of populations. Species are born, then (95) , and then die. Some live a (96) time, perhaps millions of years; some die more quickly. We have (97) the extinction of many species we know about, and we have undoubtedly sealed the (98) of others. In fact, there are undoubtedly many other species that have lived among us during our time on earth, but that have disappeared as a (n) (99) of our activities without our ever having known they existed.
It is hard to explain the rationale of many of us who are concerned about such matters. I have never seen a sea whale, (100) I don’t want them to become extinct. Moreover, I felt this way long before I understood anything about how they might be an important part of an ecosystem. Possibly such feelings merely reflect the cultural attitude that it is "nice" to wish other living things well; thus, the attitude is (101) . I feel nice.
There are, of course, more rational reasons for (102) the extermination of any species. For one thing, the kind of attitude that encourages or sanctions the destruction of other species is a threat (103) our own wellbeing. If such an attitude exists, we ourselves might (104) victim to it. living things (including us) might be expected to fare better where there is (105) for life. The extinction of other species could also threaten us (106) by simplifying the system of which we are a part or by destroying parts of the ecosystem (107) which we directly rely. For example, if we continue to poison the oceans (108) we are willing to believe only a few bottom dwellers are affected, we might (109) overstep some critical threshold and trigger the wholesale death of plankton, thus finding ourselves without a major (110) of the world’s food and with our oxygen supplies dwindling.

A．rewarded

B．returned

C．fulfilled

D．affected
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单项选择题

农业科研单位与其他经济实体(包括国内外合资企业等)，以成果、技术和资金等入股的形式，共同组织科技产品开发和承担经营风险。
这段话主要支持了这样一种观点，即科研单位与其他经济实体的合作：

A．或者以成果、技术的形式，或者以资金入股的形式

B．以成果入股、技术入股和资金入股的形式

C．以成果、技术和资金为相互承诺的形式

D．以成果、技术折合成入股资金的形式
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