Question

I soon found that the work I was doing ____ by someone else — in other words, I was wasting my time.

1. A.
   had already been done
2. B.
   has already been done
3. C.
   would be done
4. D.
   have already been done

Answer 1

A
主句I soon found是一般过去时态，宾从that the work____要用过去时态的某种形式，排除B,D；且工作已经被别人做了，要用过去完成时态。I was doing是定从，修饰the work。选A。