On his way to the airport, it ________ him all of a sudden that he had forgotten her birthday.

Can you buy me a birthday cake _____ the afternoon?— Sorry, I ambusy. I can do it _____ Sunday afternoon. [ ]

When it is winter in China, it is _______ in Australia.

It may take _________ years to make such robots .

As the saying goes, _________. So take it easy and read the question slowly within then given time when you take the test.