問題詳情

【題組】62.It may be necessary to stop ______in the learning process and go back to the difficult points in the lessons.
(A)at a distance
(B)at intervals
(C)at case
(D)at length

參考答案

答案：B
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)