cave in
phrasal verb with cave verb [ I ], verb uk/keɪv/ us/keɪv/ uk/keɪv/ us/keɪv/
(FALL)
塌陷；坍塌；塌方
If a ceiling, roof, or other structure caves in, it breaks and falls into the space below.
Because of the explosion, the roof of the building caved in, trapping several people. 由于发生爆炸，建筑物的顶部坍塌，有几个人被困在了里面。
(AGREE)
informal让步;屈服;妥协
to cave
At first, they refused to sign the agreement, but they caved in when they heard another firm was being approached. 起先，他们不肯在协议上签字，但听说我们正跟另一个公司接洽就答应了。