----I’m going to the United States.---- How long ____you ____in the States ?
What a wonder! They have finished _______ half of the project in such a short time.
The film _________ a novel by Sinclair Lewis.
Today,_________ rapid transportation and communication , the whole world seems to be smaller.
The government requested that all the people ___________ in any indoor public area.
Scientists study ___________ human brains work to make computer.