The children ______ a P.E. class on the playground when it began to rain suddenly.

Sheldon could have defeated Howard in the match, but he _______ too careless at the last minute.

We have sweaters _______ all colors _______ ￥50 each. [ ]

Miss Tang teaches _______ and we all like her class.

It is a long time _______they separated, but it won’t be long ____ they meet again.