Which book is ______ to understand, this one or that one?
---Have you ever been to Shanghai, Mary? ---Yes. I __________ there for a week with my parents last month.
--- __________ came to see you yesterday. ---Who was __________?
I can __________ be a doctor. I don’t have enough patience at all.
---Cathy, are you going to buy a flat in Shanghai? ---You must be joking. I can’t __________ one there.
It wasn’t long __________ the rain stopped and the sun came out again.