Answer:
.1. He <u>was leaving</u> the bank, when the thieves <u>took</u> his money.
2. At half past four yesterday we <u>were having</u> dinner.
1. He <u>put</u> on his coat and cap, <u>opened</u> the door and <u>went</u> out.
2. When I <u>was coming</u> to the theatre, my friend <u>was waiting</u> for me.
Explanation:
The past simple refers to events that happened in the past and that have finished while the past continuous is used when you talk about events in the past that occurred while something else was happening.
1. He <u>was leaving</u> the bank, when the thieves <u>took</u> his money. The past simple is used to talk about an action that occurred in the middle of another action that should be in past continuous.
2. At half past four yesterday we <u>were having</u> dinner. This is a past event that was hapenning at a certain time.
1. He <u>put</u> on his coat and cap, <u>opened</u> the door and <u>went</u> out. These are finished events.
2. When I <u>was coming</u> to the theatre, my friend <u>was waiting</u> for me. This is in past continuous because these are two actions that are happening at the same time.