已知△ABC与△A1B1C1的相似比为2:3,△A1B1C1与△A2B2C2的相似比为3:5,那么△ABC与△A2B2C2的相似比为____
Has your sister succeeded_____ the first place at the university this term?
我国地势第三级阶梯上最主要的地形是( )