i ___to get in touch with the manager for the last two hours but the line is always busy.

题目

i ___to get in touch with the manager for the last two hours but the line is always busy.
A tried B have tried C had tried D have been trying
the answer is D,tell me why

答案

句义 在最近的两个小时里,我一直试图和经理取得联系,但总是占线.表示“从过去某时开始到现在为止一直持续做某事”应当用现在完成进行时.eg The rain has been pouring for five hours.It has been windy for a month...