—I’m going to the United States. —How long ______ you ______ in the United States?
It’s reported that the police will soon ____ the case of two missing children.
Tom is keen _____ surfing the Internet in his spare time.
The students were completely _____ in their reading.
She missed the plane, _____ driving very fast to the airport.
My brother is really _____. He often works in his office far into the night.