B. much more expensive to build than they had been previously
C. built predominantly in the western part of the country
Chọn D
One of the first exercises in math class is ______ measure the radius of a circle.
_______ have settled, one of their first concerns has been to locate an adequate water supply.
Dick put ____ ball in ____ net in _____ second half but ____ goal was disallowed.
The computer has dramatically affected ______ photographic lenses are constructed.
Only after the atomic bomb ________ and development in the air travel _______, ______ science fiction really become popular.