The two friends ______on the Internet for three hours, and they would go on till the next morning.
Martin Cooper , a US researcher , was considered _______ the first cell phone .
He looked around and caught a man _____ his hand into the pocket of a passenger.
They walked together as far as the second crossing ____ they parted .
You may use my bike _____ that you return it by noon.
With all the problems ______, the manager left for home, _______.