I had to buy _____________ these books because I don’t know which one was the best.
A. both
B. some
C. neither
D. all
世界锦标赛的仲裁成员为:
A. 1个有资格的人
B. 2个EC成员
C. 以上都有
When navigating using GPS,what is an indicator of the geometry of the satellites that your
A. Horizontal Dilution of Precision
B. Selective Availability
C. Doppler Shifting
D. Precision Coding
很少引起AIDS患者机会性感染的病原体是
A. 巨细胞病毒
B. 卡氏肺孢子菌
C. EB病毒
D. 弓形虫
E. 新型隐球菌