we should exploit the Antarctic’s natural resources is open to discussion

If you have some difficulties ____ yourgrammar, you had better ask your teacher ____.

The meeting _________ by the time I gotthere yesterday.

I saw your uncle take a taxi to the airport. Why didn’t you drive him there? — I ______. But my car ______.

There’s no way to get to the small islandwhere my grandparents live by boating．