_____ computer games, his parents were very worried about his future.
Scientists say it may be five or six years ____ it is possible to test this medicine on human patients.
Every minute must be made full use of ____ our lessons, for the final examination is coming.
The foreigner does speak Chinese well, but of course not _____ we Chinese.
The reason _____ he refused to attend the meeting was that they didn’t give him an invitation earlier.
—Thank you for joining in our conversation tonight.—_____.