B) Past Continuous
1) Не (listened) to the music while he (was walking) in the forest.
2) I (was doing) my homework for two hours.
3) Our teacher (was explaining) us the new grammar for about 30 minutes.
4) They (were watching) Netflix the whole evening.
5) We (were having) lunch when he finally came home.
C) Past Perfect
1) She realized that she (had left) her keys at home.