2022英语周报初三第32期JXG答案

19.解:(1)a=(-3,2),b=(2,1),c=(3,-1),a十加=(-3,2) t2,1)=(-3 2t,2 t),(2分)|a b|=√(-3 2t)2 (2 t)25=8 1√(-) 5==5,当且仅当=5时取等号,即|a b|的最小值为,此时t=(4分)(2)∵a一t=(-3,2)一t(2,1)=(-3-2t,2-t),又a-t与c共线,c=(3,-1),∴(-3-22)X(-1)—(2-t)×3=0,解得t=(8分)(3)∵a一b与t b成钝角,a-b=(-5,1),a b=(2-3t,1 2t),∴(a-b)·(a b)=17t-9<0,解得长<17(10分)又a-b与t b共线时,t=-1,此时(a-b)·( b)=-(a-b)2<0∴ <且t≠-1实数的取值范围为(-∞,-1)u(-1,)< p>

【语篇导读】本文是夹叙夹议文,告诉我们“远亲不如近邻”的道理。8.A【解析】细节理解题。根据第一段 Muckprobably it is a close female friend calling to tell you thatshe has split up with her boyfriend again or perhaps simply that a good movie has just started on TV.可知最有可能来自一个朋友,故选A。9.C【解析】细节理解题。根据第三段 TV shows liktell us that our romantic relationships may not lastwe need to keep in touch with our close friends ifwant to survive.可知 rV shows like friends告诉我们亲密的朋友帮助我们面对生活中的困难。故选C。10.D【解析】推理判断题。根据最后一段 This is trueof Erika and Janes friendship. With Erika's family200 miles away, it is Jane who keeps a spare set of keysto Erikas apartment and waters her plants wheneverhe is away.可知Erka和Jane在日常生活中互相信任和支持。故选D1].A【解析】推理判断题。纵观全文,特别是最后have more to do with my life than ray paents and, therefore, I dont have to spend a lot of timeexplaining things to them. Friends are more up to datwith what is happening.可知远亲不如近邻。故选A

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