题目

He struggled through a few games but a ________knee indicated his problems were not over.A.swollen B.swell C.swear D.swearing 答案：【答案】A【解析】考查词性辨析。句意：他挣扎了几场比赛，但肿胀的膝盖表明他的问题还没有结束。A. swollen肿胀的，是形容词；B. swell肿胀，是动词；C. swear咒骂，宣誓，是动词；D. swearing发誓。后面是名词，这里表示“一个肿胀的膝盖”，用形容词，故选A。已知a＞0且a≠1，f(logax)=aa2-1(x-1x)．（1）求f（x）；（2）判断f（x）的奇偶性；（3）判断f（x）的单调性并证明．