搜题请搜索小程序“爱下问搜题”
问题 单项选择题

正态曲线下面积有一定的规律，μ±1σ的面积占总面积的()

A．50.5%

B．55.2%

C．62.8%

D．68.2%

E．69.2%

答案

参考答案：D

句型转换

Change the forms of the following sentences. 句型转换。

1. It's 7:00. (对画线部分提问)

                                                                                                  

2. Good morning. (作出回答)

                                                                                                  

3. It's time to have lunch. (同义句转化)

                                                                                                  

4. Spring Festival is in January or February. (对画线部分提问)

                                                                                                  

5. It was Sunday, July eleventh yesterday. (对画线部分提问)

                                                                                                  

查看答案
单项选择题

煤气管道安装流量孔板时，流量孔中心偏差不超过（）。

A.D/20

B.D/40

C.D/80

D.D/100
查看答案