Flying is a fast way to travel.But it is a big headache for some people.They can't help worrying about things like "Is it dangerous if we don't change our mobile phones to airplane mode（飛行模式）？"Here are some interesting facts about flying.
   Why are plane windows round？
   It's for safety.As the airplane flies higher and higher，the atmospheric pressure（氣壓）outside gets lower and lower.During the flight，the pressure inside the plane becomes greater than the pressure outside.When this happens，square（方形的） windows can break.That's because having different pressures inside and outside puts stress on the corners of square windows.But rounded corners can spread the pressure more evenly（均勻地） across the window's surface（表面），making it less likely to break.
   What happens when a phone isn't in airplane mode？
   Some passengers believe mobile phones and tablets need to be turned off because they can bring the plane down.However，this is not true.If you don't change your phone to airplane mode，pilots and air traffic controllers may hear unpleasant sounds in their headphones.This makes it harder for them to communicate.So it's still best to put your devices（設(shè)備） in airplane mode.

（1）Why is flying a big headache for some people？

Because they can't help worrying about things like "Is it dangerous if we don't change our mobile phones to airplane mode？"

Because they can't help worrying about things like "Is it dangerous if we don't change our mobile phones to airplane mode？"

（2）Is the pressure inside the plane the same as that outside during the flight？

No，it isn't.

No，it isn't.

（3）Why are round windows less likely to break？

Because rounded corners can spread the pressure more evenly across the window's surface，making it less likely to break.

Because rounded corners can spread the pressure more evenly across the window's surface，making it less likely to break.

（4）What makes it harder for pilots and air traffic controllers to communicate？

Unpleasant sounds in their headphones.

Unpleasant sounds in their headphones.

（5）After reading this passage，if you take the plane next time，what will you do？

I will change my phone to airplane mode.

I will change my phone to airplane mode.