Q624
The accident occurred when the passengers . . . . . . . .
A.
sleep
B.
had slept
C.
had been sleeping
D.
were sleeping
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
The sentence is in past continuous. We use was/were + the -ing form of the verb. We generally use the past continuous to talk about actions and states in progress (happening) around a particular time in the past. It can emphasize that the action or state continued for a period of time in the past.