1. Your room is in ______ mess! Go and put them in ______order.
A. / ; an B. a; / C. a; an D. /; /
2. —— How can we pass the time? There is half an hour before the concert begins.
—— ______ ! I will like whatever you want to do.
A. All right B. Up to you C. It all depends D. Take your time
3. Scientists are convinced ______the positive effect of laughter ______physical and mental health.
A. of; at B. by; in C. of; on D. on; at
