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淞沪会战，(徐州会战，武汉会战)

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政治经济制度对教育发展的影响和制约

一个国家的民主程度直接取决于一个国家的政体，间接取决于这个国家人民受教育的程度。

下面的短文有15处空白，请根据短文内容为每处空白白确定1个最佳选项。 It sounds all wrong-drilling holes in a piece of wood to make it more resistant to knock. But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot. The discovery should lead to more effective and lighter packaging materials. Carpenters have known (51) centuries that some woods are tougher than others. Hickory(山核桃木), for example, was turned into axe handles and cartwheel spokes (车轮辐条) because it can absorb shocks without breaking. White oak (橡木), for example, is much more easily damaged, (52) it is almost as dense. Julian Vincent at Bathe University and his team were convinced the wood’s internal structure could explain the differences. Many trees have tubular(管状的) vessels that run (53) the trunk and carry water to the leaves. In oak they are large, and arranged in narrow bands, but in hickory they are smaller, and more evenly distributed. The researchers (54) this layout might distribute a blow’s energy throughout the wood, soaking up a bigger hit. To test the idea, they drilled holes 0.65 millimeters across into a block of spruce(云杉), a wood with (55) vessels, and found that (56) withstood a harder knock. (57) when there were more than about 30 holes per square centimeter did the wood’s performance drop off. A uniform substance doesn’t cope well with knocks because only a small proportion of the material is actually (58) . All the energy from the blow goes towards breaking the material in one or two places, but often the pieces left (59) are pristine(未经破坏的). "But instead of the energy being concentrated in one place, the holes provide many weak spots that all absorb energy as they break", says Vincent, "You are controlling the places (60) the wood breaks, and it can then absorb more (61) , more safely". The researchers believe the principle could be applied to any material- (62) example, to manufacture lighter and more protective packaging. That could (63) be used in car bumpers (保险杠), crash barriers and armor for military vehicles, says Ulrike Wegst, (64) the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you’d (65) to design the substance with the direction of force in mind. "The direction of loading is crucial", she says.

A. for
B. since
C. in
D. at

下列针对抗日战争和国共内战的说法，全都正确的是( )。 ①最早把国统区的人民民主运动称作“第二战场”的是周恩来 ②抗日战争时期，“地道战”主要发生在河北平原，“地雷战”发生在胶东半岛，“鸡毛信”发生在太行山，“小兵张嘎”发生在白洋淀地区 ③在八路军总部统一指挥下发动百团大战的军区和师部包括第一一五师、晋察冀军区、第一二九师、第一二。师、决死纵队 ④第二次近卫声明提出了建立日、“满”、华“三国”合作的东亚“新秩序” ⑤1947年，中共中央撤离延安后，西北人民解放军同敌人周旋采用的战术是游击战术

A. ③⑤
B. ②③
C. ①②④
D. ①④⑤