..--- How’s your tour around the North Lake? Is it beautiful? --- It ________ be, but it is now heavily polluted (污染).
–When and where shall we meet? -We _______ meet at the station at four this afternoon.
What do you mean _____ saying “out of question”?
Water as well as other resources ______ all over the world every day.
The teaching building is _________ by many trees, some ______ over 30 metres.
They ________ to finish the project before Sunday, but they didn’t make it because of the heavy snow.