为了使泵避免发生汽蚀,下列说法正确的是:() A.有效汽蚀余量应大于临界汽蚀余量 B

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问题:

为了使泵避免发生汽蚀,下列说法正确的是:()

A.有效汽蚀余量应大于临界汽蚀余量

B.临界汽蚀余量应大于有效汽蚀余量

C.必需汽蚀余量应大于临界汽蚀余量

D.临界汽蚀余量应大于必需汽蚀余量

考点:海船船员考试船舶辅机(大管轮)船舶辅机(大管轮)题库
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With the spread of inter-active electronic media a man alone in his own home will never have been so well placed to fill the inexplicable mental space between cradle and crematorium. So I suspect that books will be pushed more and more into those moments of travel or difficult defecation (1) people still don’t quite know what to do with.

When people do read, I think they’ll want to feel they are reading literature, or (2) something serious. (3) you’re going to find fewer books presenting themselves as no-nonsense and (4) assuming literary pretensions and being packaged as works of art. We can expect an extraordinary variety of genre, but with an underlying (5) of sentiment and vision.

Translators can only (6) from this desire for the presumably sophisticated. We can look forward to lots of difficult names and fantastic stories of foreign parts enthusiastically (7) by the overall worship of the "global village’. Much of this will be awful and some wonderful, (8) don’t expect the press or the organizers of prizes to offer you much help in making the appropriate distinctions. They will be chiefly (9) in creating celebrity, the greatest enemy of discrimination, but a good prop for the (10) consumer.

Every ethnic grouping over the world will have to be seen to have a great writer—a phenomenon that will (11) a new kind of provincialism, more chronological than geographic, (12) only the strictly contemporary is talked about and (13) Universities, including Cambridge, will include (14) their literature syllabus novels, written only last year. (15) occasional exhumation for the Nobel, the achievements of ten or only five years ago will be largely forgotten.

In short, you can’t go too far wrong when predicting more of the same. But there is a (16) side to this—the inevitable reaction against it. The practical things I would like to see happen--publishers seeking less to (17) celebrity through extravagant advertising, (18) and magazines (19) space to reflective pieces—are rather more improbable than the Second Coming(耶稣复临). But dullness never quite darkens the whole planet. In their own idiosyncratic fashion a few writers will (20) be looking for new departures.

Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.19()

A.gives

B.giving

C.to give

D.give

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设f(x,y)=

,x>0,y>0,求

[*]

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读下图“北半球(部分)地区人口密度图”,完成1-2题。

1.A、B、C、D世界四大人口密集区中,以黄种人为主的是[ ]

A.A 地区

B.B 地区

C.C 地区

D.D 地区

2.F处人口稀少的原因是[ ]

A.高山

B.寒冷

C.暖湿

D.干旱

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下列我国古代科技成就中,两项都属于同一领域的是[ ]

A.《千金方》和《本草纲目》

B.《水经注》和《农政全书》

C.《缀术》和《天工开物》

D.《齐民要术》和《梦溪笔谈》

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根据GB5606-2005《卷烟》系列国家标准规定,卷烟包装与卷制质量缺陷分为A.B.C类。其中A类为严重质量缺陷,B类为较严重质量缺陷,C类为()。

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