CDMA2000-1X系统使用了哪一种扩谱方式?()
A.DSSS
B.FHSS
C.THSS
D.FDSS
参考答案:A
The Chinese are proud of the 29th Olympic Games ____in Beijing 2008.
A.hold
B. holding
C. held
D. to be
I haven't seen you for a couple of days. What have you been up _____? [ ]
A. in
B. to
C. with
D. for