1) Jake looked at the weather outside: it was grey, but it wasn't raining.
Explanation: The sentence describes an ongoing state in the past (the weather being grey) and contrasts it with another ongoing action that was not happening at that time (raining). The continuous form "wasn't raining" is used here to indicate that the action was not in progress at that specific moment.
2) You didn't answer when I phoned you this morning. What were you doing?
Explanation: The question inquires about an activity that was happening at a specific time in the past (when the phone call occurred). The past continuous tense "were you doing" is suitable because it indicates an action that was in progress at that particular moment.
3) Lucy switched off her computer, put on her coat, and left the office.
Explanation: This sentence describes a sequence of actions that Lucy performed one after another. The simple past tense "put on" and "left" are used because they indicate completed actions that happened in succession.
4) She closed the window because some children were making a lot of noise outside.
Explanation: The past continuous tense "were making" is used to indicate that the children were in the middle of making noise at the time she decided to close the window. It emphasizes the ongoing nature of the noise-making activity.
5) When I told my friends about the robbery, they didn't believe me.
Explanation: The simple past tense "didn't believe" is appropriate here because it refers to a specific reaction that happened at a definite time in the past (when the speaker told their friends about the robbery). The belief or disbelief is a complete action rather than an ongoing one.
6) She didn't hear the doorbell because she was having a shower.
Explanation: The past continuous tense "was having" is used to indicate that she was in the middle of taking a shower at the time the doorbell rang. This emphasizes the ongoing nature of the activity, which explains why she didn't hear the doorbell.