I looked for the key _______ the door, but I didn’t find it. [ ]

People celebrate Chinese New Year ______ from house to house. [ ]

Is there __________ in today’s newspaper? — Yes. Ding Junhui will take on Xiao Guodong in the first ever world ranking final between two Chinese players at the Shanghai Masters on Sunday.

Some Math problems are difficult for the students work out.

What _____you ______ at 10:00 last night?