crack ·phrasal verb
Definition: to become mentally ill Level: C2
我们担心如果他得不到帮助，他会完全精神崩溃。
We're worried he'll ___crack ___up completely if he doesn't get help.
然而，人们也必须记住，由于道格拉斯过度工作，奥利维亚过着乏味、无聊的生活，即将精神崩溃，这时纳瓦布来救了她。
Nevertheless, one must also bear in mind the fact that, since Douglas was overworked, Olivia had a tedious, boring life and was about to ___crack ___up, when the Nawab came to rescue her.
持续的压力让她害怕自己随时可能精神崩溃。
The constant stress made her fear she might ___crack ___up at any moment.