我从来不能对人开玩笑,因为我忍不住笑。
I can never play jokes on people because I can't ___keep ___a ___straight ___face.
在严肃的会议上,尽管演示文稿中有个有趣的错字,他不得不保持面无表情。
During the serious meeting, he had to ___keep ___a ___straight ___face despite the funny typo in the presentation.
喜剧演员的笑话太搞笑了,观众中没人能忍住不笑。
The comedian's joke was so hilarious that no one in the audience could ___keep ___a ___straight ___face.