问题补充：
— It is around 100 years, known to us all, the first modern Olympic Games was held.
— It really is. But were ?
A. that; was that
B. since; was it
C. after; is that
D. when; is it
答案：
A. that; was that
(答案→)B. since; was it
C. after; is that
D. when; is it
解析：考查句型It +be +some time +since从句，表示“自从……以来已经多长时间了。”本句意思为：众所周知，自从第一届现代奥林匹克运动会举办以来大约一百年了。既然是一百年前举办的，第二句当然要用一般过去时——是在哪儿举办的？比较：It is around 100years ago that the first modern Olympic Games was held. w
