the student gave a clear, crisp answer to the teacher's question.
学生干净利落地回答了老师的问题。
invalid a.不正确的,缺乏证据的;无效的,作废的。作名词时,表示病弱者,伤残者,久病者。
your ideas about the first humans are interesting but invalid.
你关于最早的人类的观点很有意思,但是缺乏证据。
a bad car accident made him an invalid.
一次严重的车祸使他变成了残疾。