---How long have you been running ? ---Since ______ .
A. two hours B. two hours ago C.I am ten years old D. for two hours
He said he_____ to my home in a week.
A. would come B. came C. comes D. will come
Sally has been swimming ______ four hours.
A. for about B. since C. about D. /
Sam ______ coins since he was eleven years old, and now he has hundreds of them.
A. collected B. had collected
C. has been collecting D. had been collecting
I had a really hard time _____studying science this term.
A. to B. with C. in D. on
Don’t ______ others when they make mistakes.
A. laugh at B. laugh with C. laugh to D. laugh
