Try to determine what surface the plane will land on so you can customize your preparations. If you’re going to be landing in water, for example, you’ll want to put your life vest on, though you need to wait to inflate it until you’re out of the plane. If you’re going to be landing in cold weather, you should try to get a blanket or jacket to keep you warm once outside.  Plot out the general course you'll be on ahead of time, so you'll have some idea of where you are when the plane crashes. If you're flying from Iowa to California, you can be fairly certain you won't be landing in the ocean. Use the time before the crash to find your exit. If the plane is going to crash, you almost always have several minutes to prepare before impact. Use this time to once again review where the exits are. If you know you’re going to crash, return your seat back to its full upright position and stow away any loose items that could become hazardous, if at all possible. Zip up your jacket and make sure your shoes are tied tightly to your feet. Then assume one of two standard brace positions used for surviving a plane crash and try to remain calm. In either position, your feet should be flat on the floor and further back than your knees to reduce injuries to your feet and legs, which you will need in order to successfully exit the craft after impact. Place your legs as far under the seat as possible to avoid breaking your shin bones. If the seat in front of you is close enough to reach, place one hand palm-down on the back of that seat, then cross the other hand palm-down over the first hand. Rest your forehead against your hands. Keep your fingers unlaced.   It's also sometimes recommended that you put your head directly against the seat in front of you and lace your fingers behind your head, tucking your upper arms against the sides of your head to cradle it. Bend forward, if there's no seat in front of you. If you don’t have a seat close in front of you, bend forward and put your chest on your thighs and your head between...

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Write a summary of the previous text in Vietnamese:
Tìm hiểu tình huống. Thu xếp chỗ ngồi của bạn hết mức có thể. Bám chặt vào ghế phía trước. Cố giữ bình tĩnh. Trong trường hợp máy bay rơi xuống nước, choàng áo phao vào người nhưng đừng làm phồng áo. Đeo mặt nạ ô-xy cho mình trước khi hỗ trợ người khác.