单项选择题
It takes about 12 seconds to reverse（）full speed ahead（）speed astern.
A.at, to B.to, from C.from, to D.at ,from
单项选择题 It was essential that the application forms（）back before the deadline.
单项选择题 Jim is sorry（）so impolite to your guest last Saturday.
单项选择题 John regretted（）ashore yesterday.
