問題詳情
33.Experts have been warning of the bealth risks caused by passive smoking
(A)at a time
(B)at one time
(C)for some time
(D)for the time
參考答案
答案：C
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)
用户評論
【步筱昕】評論
本题考查固定短语。从句中have been warning 可知，应用for some time 一段时间，at a time 每次；at one time 曾经。