hiss|hisses

猫靠近时，那条蛇发出嘶嘶的警告声。

The snake made a warning ___hiss when the cat got too close.

蛇在感到危险时会发出嘶嘶声。

The snake ___hisses loudly when it senses danger.

当演员表演得很糟糕时，观众开始发出嘘声。

The crowd started to ___hiss when the actor performed poorly.