1、C.do有义项为：完成某项活动或走完成一段路程；（车辆）以某一速度行进,达到某一速度.
eg:The car was doing 90 miles an hour.
2、D.完整句子为：why you don't do it as what you was told to.省略成分,但to不可省略.
3、A.不定代词的定语从句,后接不定式表目的.
句子分析为：do everthing (they could) to help the people.
括号中为定语成分.
这个题目选什么?为什么选这个?请大家帮个忙请问选什么呢?为什么选这个答案?my new sports car ____1