I had been looking for the book for two days____ I found it at last.( )
A: until
B: when
C: before
D: while
A: until
B: when
C: before
D: while
举一反三
- I had been looking for the book for two days____ I found it at last.
- ______ I had been looking for two days, I found her at last.
- They （） this boy for quite a few days before they found him. A: have looked for B: had looked for C: have been looking for D: had been looking for
- I had been working a couple of months ______ I had a letter from Mike. A: when B: until C: that D: while
- 这个句子的时态是______。I have been looking for my lost book for three days, but I still haven't found it.