Ex. 5. Open brackets using Past Simple or Past Continuous.
4. The scientist
(to work) in the lab when somebody
(to switch
off) the light.
5. They
(to leave) the house when we
(to arrive)
6. She
(to print out the documents when somebody
(to call).
7. It
(to start) raining while she
_(to water) the flowers
in her garden.