在军领域里，层次最高，指挥的范围最广，各项工作的“龙头”和总纲，各种活动的依据是（）
A、战术
B、战略
C、方针
D、政策
参考答案：B
Bill asked his father _____ and play football.[ ]
A. let him to go
B. let him to
C. to let him go
D. to let him to go
“先工作后判断”的循环程序结构中，循环体执行的次数最少是( )次。
A．1
B．0
C．2
D．不定
