______ have you lived with your grandparents?—About three years.[ ]

It wasn’t _____the anti-Japanese war was over _______ his parents had died two years before

I can’t find the bookstore _____ my father bought the book for me yesterday.

Will you drop ________ us tomorrow evening for a talk?—Sounds great! [ ]

How was your day off?— Pretty good! I ______ the science museum with my classmates.