---What is the boy doing?---He _____________ happily.A swims B swam C has swum D is swimming
We still gave the boy another chance ______he made some mistakes.
You can never imagine the great difficulty I had ______ her QQ number.
Yunmeng Mountain _______lies in the south of Hebi attracts the visitors both at home and abroad.
The boy ______ a piece of waste paper, and put it into the rubbish bag.
Henry speaks Chinese very well. He ______ in China since 2002.