四格表的周边合计不变时,如果实际频数有变化,则理论频数()。
A.增大
B.减小
C.不变
D.不确定
E.随A格子实际频数的变化而变化
参考答案:C
.It is said that the early European playing-cards ______for entertainment and education.
A.were being designed
B.have designed
C.have been designed
D.were designed
有以下程序段,则下列选项说法正确的是()。
A、程序编译失败
B、程序运行结果为:one.Threadtwo.Thread
C、程序运行结果不确定
D、程序运行结果是:one.two.ThreadThread