IN THE PAST THE TRIP _______VERY ROUGH AND OFTEN DANGEROUS, BUT TH...

24. - 25 DE THI HOC KI 1 MON TIENG ANH LOP 12 CO DAP AN
25 DE THI HOC KI 1 MON TIENG ANH LOP 12 CO DAP AN

24. In the past the trip _______very rough and often dangerous, but things _______a great deal in the

last hundred and fifty years.

A. is/changed

B. would be/had changed C. has been/ changed

D. was/have changed