问题
选择题
About two years ________ since the earthquake took place in Wenchuan.
A．passed
B． has passed
C．have passed
D．has been passed
答案
答案：B
题目分析：句意：自从汶川地震发生，已经大约两年过去了。since自从，引导的时间状语从句为一般过去时，主句为现在完成时，two years做为一个整体，视为单数，故选B.