To be crude and careless is an extremely bad style of work.
粗枝大葉是一種極壞的作風。
On inspection, the meat was found to be bad.
經檢查，發現這些肉是壞的。
Do you want the good news or the bad news first?
你是想先聽好消息還是壞消息？
Why should I want to make you feel bad?
我干嗎要讓你難過呢？
He was put off science by bad teaching.
教學不好使他失去了對理科的興趣。