那位老人突然跌倒在地上。

The old man suddenly ___collapsed onto the ground.

谈判失败后，整个和平协议彻底崩溃了。

The entire peace agreement ___collapsed after the negotiations failed.

老人在烈日下站了太久，突然晕倒了。

The old man ___collapsed after standing too long in the scorching sun.

轻压按钮，椅子就会自动折叠起来。

Press the button lightly and the chair will ___collapse automatically.