1 N-UNCOUNT 火箭学;航天器学 Rocket science is the study, design, and development of spacecraft. 火箭学;航天器学
2 N-UNCOUNT 高深的事;难做的事;考验智力的事 If you say that something is not rocket science, you mean that you do not have to be clever in order to do it. 高深的事;难做的事;考验智力的事