After breaking up, the girl sent a message to the boy and asked him how he was. He answered two words, no, what do you mean? How should a girl reply to him?

In this case, the boy's answer to "bad" may indicate that his current emotional state is relatively low or unhappy. Girls can properly express their concern and understanding, such as "I know you are in poor health now, is there anything I can do for you?" Or "If you need to talk or chat, I will always be here". Of course, girls also need to consider whether they are willing and able to keep in touch with this boy and what kind of contact information to leave.