Answer:
1. Ann was watching the TV at home
2. Carol and Jack were watching a film in the cinema
3. Tom was driving his car.
4. Catherine was waiting for a train at the station
5. Mr. and Mrs. Hall were walking in the park.
Step-by-step explanation:
Required
Fill in the gaps
Before questions like these can be answered, it's best to understand the tense used in the question.
The question requires that we fill in the gap with what people "were doing" at 3.
The quoted phrase is in its past continuous. So, the answers will be filled with verbs in their past continuous form.
Another thing to note is that, the verbs on the bracket will be used to fill in the gaps (but they must be in past continuous form).
So,
1. Ann is singular; so "watch" will take a singular verb
The gap will take "was watching"
2. Carol and Jack (that's two people; i.e. plural); so "watch" will take a plural verb.
The gap will take "were watching"
3. Tom is singular; so "drive" will take a singular verb
The gap will take "was driving"
4. Catherine is singular; so "wait" will take a singular verb
The gap will take "was waitng"
5. "Mr. and Mrs. Hall" (that's two people); so "walk" will take a plural verb
The gap will take "were walking"