飞机在雷暴云中、云下和云附近飞行时，都有可能被闪电击（又称雷击）中，尤其是在( )℃附近飞机被雷击的次数最高。飞机遭闪电击的高度大都在6千米以下，个别发生在11－12千米，90％的闪电击发生在4千米以下。

驾驶舱逃生口仅可以从内部操纵。The flight compartment overhead escape hatch only can be operated inside.

下列哪个舱门不在EICAS舱门简图页面显示？
Which door not indicated at the doors synoptic page?

CRJ900系列飞机有（）个应急出口。
The CRJ900 series aircraft have（）emergency exit。

CRJ900系列飞机有13个外部门（包括选装的后勤务门）。其中3个仅能从外部操作：The CRJ900 series aircraft have 13 external doors (including optional AFT Service Door). External doors. Three of them can only be operated from outside:

CRJ900系列飞机有13个外部门（包括选装的后勤务门）。其中有多少个可以用来应急撤离？The CRJ900 series aircraft have 13 external doors (including optional AFT Service Door). How many of them can be used for emergency evacuation?

旅客舱门警告和警戒信息显示在：Passenger door warning and caution messages are displayed:

舱门信息显示在：Door information is displayed on..

如果左翼上的一个应急出口打开：If one of the left over-wing emergency exit is opened?

音响警告DOOR 响起当：An aural DOOR is sounded when?

登机门楼梯允许的最大人数是：The maximum number of people permitted on the passenger door stairway is?