The Korean girl can speak Chinese without difficulty because she ______ in China for years.
A. stay B. will stay C. has stayed D. stayed
Sam denied ______ computer games for hours in the net bar yesterday afternoon.
A. to play B. playing C. play D. played
You’d better ______ ask old granny for help because her memory is getting poorer now.
A. not B. don’t C. not to D. to not
One ______ easily lose his way when he visits or comes to a new place.
A. may B. must C. need D. should
You will surely realize your dream of being a scientist ______ you give it up halfway.
A. though B. if C. unless D. since
This pet shop is losing its customers ______ its staff work slowly and often make mistakes.
A. so B. because C. until D. although
