老人看到那条大狗时，害怕得浑身发抖。

The old man ___trembled with fear when he saw the big dog.

看到蛇时，她的腿不由自主地发抖。

Her legs ___trembled uncontrollably when she saw the snake.

当她听到这个消息时，双手因担忧而微微颤抖。

Her hands ___trembled with worry when she heard the news.