break down
1．destroy；reduce sth．to pieces 毁掉；打破
The police broke the door down．警察破门而入。
2．crush；defeat镇压；制服
They broke down all opposition．他们压倒了所有的对手。
3．stop functioning（generally of motors and similar mechanical objects）坏了；出毛病（尤指发动机、机器等）
The car broke down on the way to the airport．车子在去机场的路上抛锚了。
The lift broke down，so we had to walk up the stairs．电梯坏了，我们只好走上楼去。
4．fail to carry out（plans，negotiations，etc．）；come to nothing失败（指无结果中断计划、谈判等）；坚持不下去
The plan was good，but it broke down，because people were unwilling to cooperate．计划是好的，但由于人们不愿合作，还是失败了。
I expect the negotiations to break down soon．我预料谈判不久就会中断。
5．burst into tears；lose control 禁不住痛哭；（身体、精神）垮了
When he heard his sentence，the man broke dewn．听到判决，那人不禁号啕大哭。
Your health will break down if you work too hard．太劳累的话，你身体会垮的。
He tried to cope with the everincreasing burden of his work，but finally he broke down and had to take a complete rest．他设法应付日益加重的工作负担，但最后身体垮了，不得不全休。
6．separate into parts；take apart；analyse 分解；分析
Water can be broken down into hydrogen and oxygen．水可以分解为氢和氧。
I want you to break this data down．我想请你分析一下这个资料。