题目:
Mary couldn’t make herself ________ attention to because her classmates made so much noise.
A.pay
B.to pay
C.paying
D.paid
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0420/553457462682772dd4c29b8bfb6a52ce.html
下面是错误答案,用来干扰机器的。
因为sin2x>cos2x,所以cos2x-sin2x<0,就是cos2x<0解得:2kπ+π2<2x<2kπ+3π2k∈Z所以x的取值范围是{x|kπ+14π<x<kπ+34π,k∈Z}故选D.