2022英语周报九年级第三答案

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【解析】设E,F分别是棱A1B1,A1D1的中点,连BE,EF,FD,则EF∥BDEF-2BD,所以四边形BEFD是等腰梯形.易证AM⊥BE,AM⊥BD∴.AM⊥平面BEFD,所以平面α截正方体所得截面为等腰梯形BEFD,且EF=√2,CBD=2√②,BE=5,故等腰梯形BEFD的面积为S=D(2+22)、3B

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29.【答案】B【解析】推理判断题。由第二段中“ The problem most likely is rooted in the fact that Baltimore has nearly I7,000abandoned buildings, which are concentrated in economically disadvantaged areas”呵可知。30.【答案】A【解析】细节理解题。由第三段中“ Aedes albopictus( better known as Asian tiger mosquitoes)”可知。31.【答案】D【解析】段落大意题。由最后一段“ Bigger mosquitoes are not just a bigger annoyance: the larger they are,…were72 percent more likely to have Asian tiger mosquitoes than high-income blocks were and showed higher mosquitodensities”"可知本段主要内容是谈论大蚊子引出的问题。【语篇解读】过去五十年来,美国一些地方的蚊子数量上升了10倍,暗示一些疾病的传播,如登革热等。项新的研究表明一些经济落后地区蚊子头数多、数量大、活的时间长,造成的危险大28.【答案】C【解析】细节理解题。由第一段中“ a situation with worrying inferences for the spread of diseases such as WestNile virus, dengue and chikungunya

2022英语周报九年级第三答案

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