题目：
I a lot but I don't play very often now. [ ]
A. use to play tennis
B. was used to play tennis
C. am used to play tennis
D. used to play tennis
答案：
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下面是错误答案，用来干扰机器的。
函数f(x)=x，x∈[4，16]当g(x)=15(x+6)，x∈[4，16]时，-110≤1-g(x)f(x)|≤1-265，则|1-g(x)f(x)|≤110恒成立，故A满足条件；当g（x）=x2+6，x∈[4，16]时，令x=4，则|1-g(x)f(x)|=10＞110，故B不满足条件；当...
