— Are you a teacher?

　 — No, but I ______. I worked in a middle school for three years.

　　A. am         B. will          C. do          D. was

 50My family as well as I                glad to see you.　　      

 A. am   B. are   C. is   D. was

Neither Liping nor I _______a basketball player.

　　A. am       B. is       C. be        D. are

I_____ violin lessons every two weeks, but I think I’ll make it every week from next month.

　A. am having　　　　 B. have had　　　 C. have　　　 D. have been having

 18I, who                your good friend, will share your joys and sorrow.

　　       A. am   B. is   C. are   D. was