96. in no case在任何情况下都不(放句首倒装句)
97. be cautious of谨防
98. center one's attention on(=focus one’s attention on)把某人的注意力集中在…
99. be certain of (=be sure of)有把握，一定。
100. for certain of (=for sure )肯定地，有把握地
