Had I been a little more careful,I________such a foolish mistake. [ ]

The scientist knows nothing about the matter, because he is always ______ himself in scientific study.

The teacher told Tom to sit ______ in class

.— Mr White didn’t come last night, did he?　— NoWe _____for him A whole night was wasted

Paul is really considering __ himself to __ those children in the earthquake-hit area.