—Have you found the missing?couple in the mountain ?
—No, but we hard to get in touch with them．
A. have tried
B. have been trying
C. had tried
D. had been trying ．
网友回答
A. have tried
(答案→)B. have been trying
C. had tried
D. had been trying ．
解析：可联系答.案.网客服索取。