求助白勇第二章第20题！

Many writers of modern English have acquired careless habits that damage the clarity of their prose, but these habits can be broken if they are willing to take the necessary trouble.

A.but these habits can be broken

B.but these habits are breakable

C.but they can break these habits

D.which can be broken

E.except that can be broken

正确答案是C。但是我不明白C不就是  句子1，句子2  结构吗？这个结构不是错的吗？请帮我解释一下谢谢！

这个帖子为什么没人回呢~~

第二句不是，but的结构吗？but是连词就可以连接句子了呀~~

svo，svo错误，svo，连词（and/but）+svo就对了呀~