Past Indefinite? or Past Perfect? Choose the correct tense form.
I didn't forget how it all (happened, had happened).
2 We knew that Bob (arrived, had arrived) already
3 Jack's parents were, had been) in New York a month ago.
4 Lucy thanked Mike for what he (did, had done) for her.
5 Joan (knew, had known) the name of each street in their town,
6 Bill couldn't come to school because he (fell, had fallen) ill.
7 In the morning snow (covered, had covered) all the cars.
8 The girl was surprised because she (didn't see, hadn't seen) such an amusing a
strange animal before,
9 The tennis players (started, had started) the game late because of the rain,
10 The bus driver (stopped, had stopped) when he saw the red light.