Up to now, we _______________ (not receive) any news from her.
A. hadn't received
B. haven’t received
C. is received
D. are received
I had intended to call on you yesterday, but someone____________(come) to see me.
A. come
B. comes
C. is coming
D. came
When Tom was a little boy, he already knew the sun________ (be) the center of the solar system.
A. are
B. be
C. is
D. has
I have worked here since I ________ (graduate) from college.
A. graduate
B. graduated
C. graduates
D. has graduated