You will find the game is not so difficult to play ______ you understand its rules.
A. until B. since C. before D. once
The building, ______ in the shape of an egg, is now just for tourists.
A. designing B. designed C. to be designed D. having designed
Remember to take a breath of ______ fresh air and have some exercise each day. It will make ______ difference.
A. /；a B. the；a C. /；the D. a；the
They are forbidden _____, for they are still middle school students.
A. to smoking B. to smoke C. smoked D. smoke
We have the most population in the world, most of it _____ farmers.
A. to be B. is C. are D. being
_____ at the back of the theatre, the girl couldn’t see ZhouJielun clearly.
A. Seating B. Sited C. Seated D. Seats
