Mr. Richard was disappointed that many students who had signed up for his adventure course _______ at the last moment.
A.left out
B.got out
C.passed out
D.dropped out
网友回答
D解析考察词组辨析。Leave out 遗漏，省去 get out 离开 pass out 昏倒，失去知觉 drop out 退出，退学句意为，理查德先生非常失望，因为很多报名参加他的冒险课程的人在最后一刻选择了退出。