— When did you become a volunteer?
— Two years ago. I _____this group since then.
A. have joined in
B. have taken part in
C. have been in
D. have been to
letters since then, but I haven't finished them yet.
A. have written
B. have been writing
D. has been writing
—When_____ you_____teaching in our school, Mr. Smith?
—I_____here since 1998.
A. did, started; have been teaching
B. did, start; taught
C. did, start; have been teaching
D. have, been starting; taught
1. The film started fifteen minutes ago. The film has _______ for fifteen minutes.
2. To protect the environment is our duty. ____ is our duty ________ the environment.
3. I don't want to go to work. I'd rather stay at home. I'd rather stay at home ______ going to work.
4. With the help of the teacher, I found my lost watch. _______ the teacher, I found my lost watch.
5. Susan has been in this city for more than ten years. _____ more than ten years _______
Susan ________ to this city.