I/ Give the correct form of verbs in brackets:
1. I (wait) for …………my friend outside the stadium when he (arrive) ………… .
2. While he (watch) …………….. 7o’clock news, the phone (ring) ……………….
3.Mrs. Smith (invite)……… Mrs.Quyen to have dinner while Mrs.Quyen (visit)…………… the USA.
4. When I (come) ……………….., they ( do) ……………….. their homeworks.
5. How fast ………… the boy (ride) ……… when the accident (happen)…….. ?
6. It (rain) ………… while Tuan and his brother (play) ………….. soccer yesterday.