To be crude and careless is an extremely bad style of work.
粗枝大叶是一种极坏的作风。
On inspection, the meat was found to be bad.
经检查，发现这些肉是坏的'。
Do you want the good news or the bad news first?
你是想先听好消息还是坏消息？
Why should I want to make you feel bad?
我干吗要让你难过呢？
He was put off science by bad teaching.
教学不好使他失去了对理科的兴趣。