oh,you should learn this in chinese life.there are so many this situation.like 回答 you can cut it to 回 or 答.it is chinese usual practice.every chinese charactor has it own meaning.you can use them by making them up or just one word is ok sometime

回答we can cut it to 回. is right.cut it to答 also is right 回答、回、答have the similar means.All of them mean answer. so we can cut 回答 to... however,不好(mean:no bad)we can cut it to 不only. 不means bad ，no to. but 好means good yes. so we can cut it to 不only. all in all. if they mean the same or similar meaning you can cut them for short

And English usage is similar to most nouns can be omitted, repeated also

You must fully understand the meaning of the word you want to say. ex:"回答“means "answer" but "回家" means “go home”. you can not only use "回" for this two meaning. Pls pay more effort to got the key meaning of the Chinese word, then you can, otherwise don't try it.

When your hair is long, you may be cut it. So feeling is needed , to cut it or not to cut it.