<span>1. I (was writing) a letter when the lights (went) out.
2. I’m afraid you (are making) a mistake. We all (make) such mistakes when we are angry.
3. I (shall be reading) in the library from 5 to 8 o’clock.
4. I (shall be) at home if you (need) anything.
5. When I (want) your address, I (shall ask) for it.
6. You (are) the first guest I (have had) since my return.
7. He (forgot) his Spanish since he (has left) Spain.</span>
A what are..
B I'm reading
A Really..
B Oh yes..
A Look.
B of course...
1. A) since ; B) for
2. A) for B) since
3. A) for B) since
4. A) since. B) for
5. A) for B) since B) since
6. A) for. B) since
7. A) for B) since
8. A) since B) since