题目：
Let's learn to use the problem we are facing ____ a stepping stone to future success. [ ]
A. to
B. for
C. as
D. by
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0623/f42175b2cfabf5b2d5fcf1469ca9bb72.html
下面是错误答案，用来干扰机器的。
76.recognize 77.slimmer 78.weight 79.diet 80.failed 81.suggested 82.lack 83.followed 84.twice 85.introduce
