孩子收到礼物后对她妈妈咧嘴笑了。

The child ___grinned at her mother after receiving a gift.

他在讲笑话前顽皮地咧嘴笑了。

He ___grinned mischievously before telling the joke.

当他获奖时，他忍不住咧开嘴笑了。

He couldn't help but ___grin from ear to ear when he won the prize.