BEFORE AIRPLANES WERE INVENTED, TRIPS ACROSS THE WORLD _______ MUC...
19. Before airplanes were invented, trips across the world _______ much longer and more difficult
A. had been
B. were
C. have been
D. was
19. Before airplanes were invented, trips across the world _______ much longer and more difficult
A. had been
B. were
C. have been
D. was