The scientists ________ on the new medicine for two years. They will succeed in no time. 

— They say there’s a new clothes store nearby.                          — Yes, and it________ for no more than two weeks. 

This morning the police ______ to the scene of the crime when it began to rain. 

-- Why are you in such a hurry, Mike? --- There ________ an NBA basketball game in ten minutes.

 —Linda, together with her parents, ______up the mess in the park at the moment.—It’s meaningful to be a volunteer. Let’s join them.