Every year a flood of farmers arrive in Shenzhen for the money­making jobs they ________ before leaving their hometowns

Where did you first meet your boyfriend?—It was in the department store ______ he worked.

He got up very early that day ________ hecaught the first train

Many British people have noticed that butterflies _______ from its natural habitats during the past several years

Don’t promise anything ________ you are one hundred percent sure.