Here are the best answers to complete each sentence:

Question 1: The manager ___ the store before I arrived.
Answer: B. had closed

Question 2: When we see Mr. Minh tomorrow, I ___ him of that.
Answer: A. will remind

Question 3: When I got home I found that water ___ down the kitchen walls.
Answer: B. was running

Question 4: After he ___ his English course, he went to England to continue his study.
Answer: B. had finished

Question 5: While my father ___ a film on TV, my mother was cooking dinner.
Answer: B. was watching

Question 6: When I came to visit her last night, she ___ a bath.
Answer: B. was having

Question 7: Please send us a postcard as soon as you ___ in London.
Answer: D. had had