16.—Where is Lily, Lucy? I cannot find her anywhere. —She_________have been off long. I saw her clean the window just now.
It's required that mineral resources _______hand in hand with the local environment protection.
The faces of four famous American presidents on Mount Rushmore can be seen from a ________of 60 miles.
It is reported that a man ________off an old lady in the street yesterday.
I'll trade you my stamp collection _______your model boat.
Their faces ______after the long-term misunderstandings were________.