如图所示，光滑水平面OB与足够长的粗糙斜面BC相接于B点，O端有一竖直墙面，一轻弹簧左端固定于竖直墙面，现用质量为m₁的滑块压缩弹簧至D点，然后由静止释放，滑块脱离弹簧后经B点滑上斜面，上升到最大高度，并静止在斜面上，不计滑块在B点的机械能损失．若换用相同材料、相同粗糙程度、质量为m₂（m₂＞m₁） 的滑块压缩弹簧至同一点D后，重复上述过程，下列说法正确的是（   ）

Valentine's Day(情人节) is on February 14th every year. On this day, people send valentines(情人卡)to their loved ones, Valentine's Day is a special time to tell how much you care about a person.
Many people send candy in hearted shaped("心"状的)boxes to people they love. Flowers are also presents that people send on Valentine's Day. Valentine cards with words are often used by many people.
Can you guess who gets the greatest number of Valentine cards in the United States each year? Is it mother or father, sister or brother? Is it uncle or aunt? Is it the special friend? No, it isn't!
Mothers get a lot of cards, but school teachers get the most each year. Do you know who sends the most? Children do. Children send five times as many on February 14th as adults do.