During takeoff and landing on an airplane, why are we required to put our seats and trays to the upright position?在飞机的起飞和降落的时候，为什么要求我们调整好座椅靠背，收回小桌板呢？
The reason F/As ask you to move the seat to the upright position is that it widens the space in front of the seats behind and locking your tray table up keeps your row clear of obstructions to egress. This is the same reason why all carry on bags "must fit completely underneath the seat in front of you", as any bags sticking out too far could create a tripping hazard in the event an emergency egress is needed.
空姐要求移回座椅靠背是为了给座椅之间留出足够的空位，把小桌板锁回椅背后面是为了保持每排出入通畅。飞机上一般要求随身带的包要能完全放到座椅下方也是因为这个原因，如果包太大了，一旦发生紧急事件，会给人逃生造成障碍。
It is true that most accidents happen on takeoff and landing. Aviation safety studies have shown that approximately 90% of all aviation accidents occur during the first two minutes or the last four minutes of flight. Hence, those are the two times when a sudden emergency egress could become necessary.
有个事实是大部分的飞行事故都发生在飞机起飞和降落的时候。航空安全研究显示所有的飞行事故中大约有90%都发生在开始两分钟或者最后四分钟的时候。因此，这两个时间段飞机上会要求给紧急通道留出位置。
Why are we required to pull up airplane window shades during take-off and landing?为什么我们被要求在飞机起飞和降落的时候打开遮光板呢？
If there's an accident and the lights go out, at least you have light coming in from outside.
如果有事故发生，光源不起作用了，至少你还有外部光线照进来。
Also, you can see the conditions outside more easily.
另外，你也能更轻松地看到外面的情况。
The idea is to match the outside lighting as much as possible so that passenger's eyes don't have to adjust if they have to get out quickly.
还有个目的是尽量和外部光线保持一致，这样一旦乘客需要迅速逃到外面去的时候眼睛就不需要调整内外的光线差了。
沪江小编：由此可见，飞机上每一项操作，都是有安全考虑的，春节大家回家过年，大多需要飞机火车等交通工具，一定要记得听从工作人员的安排哦。
最后，这几个词汇顺便学习一下吧：
飞机的小桌板英语叫做tray table，飞机上的遮光板，不叫curtain，叫 window shade 哦
春节在家不虚度，备战口译，就上沪江网校寒假班
