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合成培养基（synthetic medium）

【参考答案】

由化学成份完全了解的物质配制而成的培养基，也称化学限定培养基。选择培养基：在培养基内加入某种化学物质或去除某些营养物质......

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（）领域始终是社会生活中对科学技术的最新成就利用得最快最多的一个领域 A. 教育 B. 通信 C. 经济 D. 军事

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The problem with today’s housing crisis, politically, is that it is justnot all that visiblE.At the end of the Second World War, families with kids(1) _ crammed _ _ into shared houses. In 1946,more than 46,000 families took over military camps, empty hotels and flats.That was a (2) dramatically housing crisis—one that politicians couldn’t deny existeD.Today’sdoes not come close: most people still have somewhere to livE. It is nonetheless real, and (3) _______ ofpolitical attention. But the question of exactly why our expensive homes (4)_______ a crisis is more subtle than it can appear. Since 1973 at least, thetotal number of “dwellings” has climbed far faster than the population. How isthis possible, given that building rates have collapsed? And doesn’t it meanthat there isn’t really a housing crisis? First, in the 1960s and 1970s, social housinghelped people move from broken crowded houses into shiny new (5)______,typically with much more spacE.Average household size fell (6) ______, even asthe average house got bigger. Though the housing stock increased by less thanthe rate of building, everybody got a lot more space in which to livE. In recent decades, by (7) ______, everyonehas got a lot less spacE.We have had relatively little new building, butsomehow we have magically created lots of new housing. Almost anywhere inLondon, especially in the outer-suburbs, houses have been turned into flats.Essentially, so far, the housing crisis has been solved by (8) _______ ourhomes to make way for the (9) ______ population growth. All this is evidence ofa growing (10) ______ on spacE.

A.That
B.

C.

D.Essentially,
E.

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