20. The police still have I found the lost child, but they’re doing all they .(A) can(B) may(C) must

問題詳情

20. The police still have I found the lost child, but they’re doing all they .
(A) can
(B) may
(C) must
(D) should

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