别理那个傻瓜，他连最简单的数学题都不会做。

Ignore that ___dumb, he can't even solve the simplest math problem.

他始终保持沉默，面对指责一言不发。

He remained completely ___dumb when faced with the accusations.

她尖锐的问题让整个房间的人都哑口无言。

Her sharp question ___dumbed the entire room.