在对开发完毕的新频道和栏目的测试中,负责对页面版式、页面功能、页面链接等方面进行测试的是()。
A.网络编辑
B.测试工程师
C.测试编辑
D.专业测试机构
参考答案:A
能力拓展,补全对话。
A: Good morning. 1._____are you from?
B: I'm from America.
A: Do you work in a middle school?
B: 2._____, I do. I 3._____English.
A: Can you 4._____Chinese?
B: Yes, a little. I go to Chinese classes every week.
A: 6._____ have you been in Beijing?
B: For three years.
A: Do you 7._____any children?
B: Yes, I have a son and a daughter.
A: Are they here8._____you?
B: Yes, they are.
1._____ 2.______ 3._____ 4._____5._____ 6._____7._____8._____
Given P(X =2, Y= 10) =0.3, P(X=6, Y=2.5) =0.4, and P(X =10,Y=0)=0.3, then Cov(XY) is:()
A. -12.0.
B. 24.0.
C. 6.0.