问题
— Did you find the missing couple in the mountain yesterday?— No, but we________to get in touch with them ever since. [ ]
A: have tried
B: have been trying
C: had tried
D: had been trying
B: have been trying
C: had tried
D: had been trying
正确答案是：
同类题型
________ honest is the first thing people should learn.
he girl has fallen off her bicycle,and her knees _________.
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The village hasdeveloped a lot ______ we learned farming two years ago
They hurried to the train station, it was too lateThey had to wait another ten minutes