题目

Cyber Cafe computer centers are found in many cities around the world. Now, a few American high schools are opening these centers. For example, high school in the state of Maryland began operating a Cyber Cafe last March. All students at Bethesde-Chevy Chase High School in Bethesda can use the Cyber Cafe. But school officials say I especially helps students who have no computer or cannot use the Internet at home.   The officials say thirteen percent of the students at the school are from poor families. Many student have arrived in the United States from poor families. Many students have arriv跳水运动员在向下压跳板的过程中，压跳板的力的作用效果使跳板发生___▲______跳板弹起过程中，跳板推运动员的力的作用效果是使运动员的_____▲_____发生改变．