下列事例中属于应用了重力的方向的是( )
A:检查相框是否挂正
B:用力拉弹簧
C: 敲打钉子
D:往前推车
—My teachers often encourage me _____________ more friends but I find it difficult.
— Your teachers' idea is right. The more friends you make, __________ you will be.
经历了近半个世纪之久的资产阶级革命是____。