他失望地把试卷揉成一团扔进了垃圾桶。

He disappointedly ___crumpled the test paper into a ball and threw it in the trash can.

在激烈的比赛中，他因体力不支突然瘫倒在地。

During the intense match, he suddenly ___crumpled to the ground from exhaustion.

这张纸揉成一团后变得皱巴巴的。

The paper is ___crumpling after being squeezed into a ball.