问题
选择题
The GPS, originally _______ by the U.S. military, covers the whole world.
A. developing
B. to be developed
C. developed
D. having developed
答案
答案:C
The GPS, originally _______ by the U.S. military, covers the whole world.
A. developing
B. to be developed
C. developed
D. having developed
答案:C