防爆外壳严重变形长度超过（）mm，同时凹凸深度超过_5_mm即为失_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

防爆外壳严重变形长度超过（）mm，同时凹凸深度超过_5_mm即为失爆。

A、30、3

B、40、4

C、50、5

D、60、6

答案

参考答案：C

填空题

根据下表提供的信息完成句子。

Xiangyang Middle School: Activity Survey

Activity	Every day	Twice a week	Three or four times a week
Exercise	15%	10%	75%
Surf the Internet	5%	10%	85%
Play football	95%	0%	5%
Read English books	99%	2%	100%
Watch TV	85%	55%	23%

1._____ students exercise every day.
2._____ the students read English books three or four times a week.
3._____ students watch TV every day.
4._____ student plays football twice a week.
5._____ students surf the Internet twice a week.

填空题

根据彩色多普勒二次色原理，红色与绿色混合产生（），蓝色加绿色产生（）。