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问题 单项选择题

油水分离器停用前，应引入海水继续运行（），停泵后关闭油水分离器的（）以减少内壁氧化腐蚀。

A．15min/进口阀

B．15min/进出口阀

C．30min/出口阀

D．30min/进口阀

答案

参考答案：B

单项选择题

Increasingly, the development of tourism is seen to have an effect on the environment. Erosion (磨损) is one problem. The steps and stones of major popular (51) like Shakespeare’s birthplace or Stonehenge (巨石阵) are literally being worn away by millions of foreign feet. The (52) in the case of Britain’s best known prehistoric monument has been to use railings to keep visitors at a distance. Such measures can hardly be (53) in the house of the Bard, however, where tourists want to enter the actual building.

Overcrowding in cities, towns and villages is (54) problem. Traffic jams are an outcome. In narrow roads, tourist vehicles cause congestion. (55) traders and residents cannot get around to do their work. Car parks fill up, (56) strangers park their cars where they can: in streets, across gateways, in lay-bys, or even in (57) driveways. This causes obstruction. The sheer weights of in-comers can be a hazard. Thus Venice, a city built for half a million inhabitants, is (58) by another half million who populate the city daily in the tourist (59) —eight million visits each year. The mayor recently decided to (60) visitors to 90,000 a day. the only way to save the city from overcrowding.

52().

A.measure 

B.approach 

C.remedy 

D.means
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单项选择题

新鲜冰冻血浆（FFP）是在采集（）小时内，以一个单位的全血中分离出来，在-20℃或更低的温度下快速冰冻，并加以保存的血浆。

A.4

B.10

C.8-24

D.6-8
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