----Have they finished the project?---- Yes. By the end of last month, they ______ it. Now they ______ on a new one.

 I _______ up here night after night for weeks now. You see, I _______ to give you a surprise. 

The whole family _______ to Shanghai for holiday next week.

------What's the matter with Tim? ------Oh, Tim's cell phone was left in a taxi accidentally, never ________ again.

My friend has returned from the UK. She ______ at Oxford for four years, during which we communicated with each other on the Internet.