He had to be reminded two or three times ________ he could avoid making the same mistake

The car was completely _____ and the driver seriously injured.

u swim in a river or lake, be sure to investigate is below the water surface. Often there are rocks or branched hidden in the water.

下面各句中加点词语的解释有误的一项（ ）

April Fool’s Day __________ on the first day of April, but people sometimes forget the meaning of the day.