Many people in America/the USA /the US often prefer to move houses rather than settle down.
①过滤 ②蒸发 ③溶解 ④向容量瓶转移液体.
4+2+10=____
18-10-2=____
8-2+10=____
为了提高滑轮组的机械效率,下列措施中可行的是( )