1. This is a very difficult math problem that the students can't ______.
A. work on it B. work at C. work it out D. work
2. Driving a car is not as difficult as you imagine, if you _____ the rules.
A. depend on B. understand C. turn to D. stick to
请问这两道题选什么答案,怎样理解句子意思?
第一题的D选项,是work out 少了一个单词