题目

In China, safety education is becoming more and more important now. It helps students learn more about _______ they should do to keep themselves safe. Stampedes(踩踏) and fires are the main _______ at school.A stampede always happens in _______ places. When students around you begin to push(推), just stand there and try to hold onto something. If you _______ in the crowd, move to one side and protect your head with your hands _______.When there’s a _______, leave the classroom quickly. It’s better to put _______ over your mouth and nose. In this way, you won’t breathe(呼吸) in smoke将抛物线y=5x2向左平移2个单位，再向下平移3个单位，得到的抛物线是A.y=5（x+2）2+3B.y=5（x+2）2-3C.y=5（x-2）2+3D.y=5（x-2）2-3