Question

It ___ 6 years since we left middle school

1. A.
   was
2. B.
   had been
3. C.
   has been
4. D.
   were

Answer 1

C
考查固定句式 It is / has been +时间段 +since +主语+动词过去式。题意为：自从我们初中毕业已经六年了。故选C。