Radio communication()for many years and he
题型:单项选择题
问题:
Radio communication()for many years and helps to save tens of thousands of lives.
A.has been used
B.have been used
C.has used
D.have used
Radio communication()for many years and helps to save tens of thousands of lives.
A.has been used
B.have been used
C.has used
D.have used