气流流动时的摩擦阻力为
参考答案：A
Where were you just now? ________ Jack called you on the phone. [ ]
A. Some
B. Certain
C. One
D. Another
执行下列命令后，显示的结果是( )。 X=50 Y=100 Z=“X+Y” 50+＆Z
A) 50+＆Z B) 50+X+Y C) 200 D) 数据类型不匹配
