Rio de Janeiro still has a lot of things _____ to prepare for the 2016 Olympics.

Would you please drive more quickly? My plane will_____in twenty minutes.- —I want to but safety comes first.

From what he has said, let’s make a ________ guess about how the accident happened.[ ]

Once ____, Mount Tai will never beforgotten.

Hi, Susan, I didn’t see you at the party.— Oh, I ____ for an English test.