THE STUDENTS WERE TIRED. THEY___ HARD ALL MORNING.B. SHE NEVER WEN...

18. The students were tired. They___ hard all morning.

B. She never went to Paris without buying a new dress.

A. had been working B. worked

C. She never bought a new dress without going to Paris.

C. have been working D. had worked

D. She never bought a new dress when she went to Paris.