) Present Continuous или Past Continuous
1. You (to test) new equipment when I rang you up yesterday?
2. He (to install) a new program now?
3. Why she (to be) busy when I saw her yesterday?
4. When I noticed my friends, they (to sit) and (to write) something hurriedly.
c) Past Simple или Past Continuous.
1. When we (to go) home, we (to see) many people in the yard.
2. When Henry (to fix) the roof, he (to find) a nest.
3. When he (to paint) the ceiling, he (to break) the window.
4. When I (to wash) the floor, I (to find) my old mobile under the sofa.