【单选题】Almost all cell phones sold in Canada are sold at subsidized prices, with expensive plans. Almost all cell phones sold in Europe are sold at full price with cheaper plans. A cell phone manufacturer kn...
【简答题】Almost all the fatty acid molecules in a cell are covalently linked to other molecules by their ____________ group.
【多选题】下列第一类防雷建筑物防闪电电涌侵入的措施正确的是:()。
B.
在入户处应将电缆的金属外皮、钢管接到等电位连接带或防闪电感应的接地装置上
C.
当全线采用电缆有困难时,可采用架空线路,架空线与建筑物的距离不应小于5m
D.
采用架空线路时,在电缆与架空线路的连接处,尚应装设户外型电涌保护器
【简答题】设r为圆的半径,则弧长为34r的圆弧所对的圆心角的角度数为__________.
【单选题】The central idea of cell phones is that you should be connected to almost everyone and everything at all times. The trouble is that cell phones assault your peace of mind no matter what you do. If you...
【简答题】Cell phones are so cheap that almost all people can afford it. _____ you go, you can see people holding cell phones doing different things. Our life style has changed greatly _____ of the widespread ...
【简答题】Smoking was banned on almost all ______ in 198
【多选题】第一类防雷建筑物防闪电电涌侵入的措施包括:( )
A.
室外低压配电线路应全线采用电缆直接埋地敷设,在入户处应将电缆的金属外皮、钢管接到等电位连接带或防闪电感应的接地装置上。
B.
当全线采用电缆有困难时,应采用钢筋混凝土杆和铁横担的架空线,并应使用一段金属铠装电缆或护套电缆穿钢管直接埋地引入。
D.
在电缆与架空线连接处,尚应装设户外型电涌保护器。电涌保护器、电缆金属外皮、钢管和绝缘子铁脚、金具等应连在一起接地,其冲击接地电阻不宜大于10Ω。
【简答题】当全线埋地有困难时,第一类防雷建筑物的室外低压配电线路应使用一段_______或_______埋地引入建筑物。
【单选题】Driving while talking on a cell phone is almost as dangerous as driving after drinking.