问题
单项选择题
在高层住宅设计中，需设置两部电梯的住宅最低层数是( )。
A．10层
B．12层
C．15层
D．18层
答案
参考答案：B
解析：《住宅设计规范》第4.1.7条规定，十二层及以上的高层住宅，每栋楼设置电梯不应少于两台，其中宜配置一台可容纳担架的电梯。
搜题请搜索小程序“爱下问搜题”
在高层住宅设计中，需设置两部电梯的住宅最低层数是( )。
A．10层
B．12层
C．15层
D．18层
参考答案：B
解析：《住宅设计规范》第4.1.7条规定，十二层及以上的高层住宅，每栋楼设置电梯不应少于两台，其中宜配置一台可容纳担架的电梯。
| As viewed from space, the Earth’s distinguishing characteristics are its blue waters and white clouds. Enveloped by an ocean of air consisting of 78% nitrogen and 21% oxygen, the planet is the only one in our solar system known to harbor life. Circling the Sun at an average distance of 149 million km (93 million miles), the Earth is the third planet from the Sun and the fifth largest planet in the solar system. Its rapid and molten nickel-iron core give rise to an extensive magnetic field which, coupled with the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Most meteors burn up in the Earth’s atmosphere before they can strike the surface. The planet’s active geological processes have left no evidence of the ancient pelting it almost certainly received soon after it was formed. The Earth has a single natural satellite-the Moon. |
Approximately how much of the Earth’s atmosphere is nitrogen
A．One-fourth
B．One-half
C．Three-fourths
D．All of it