If you want to see a doctor, you can go to the ______.
A:hospital
B:library
C:cinema
Your room is____ your brother's,but much____ than his.
桌面上有形状大小相同的白球、红球、黄球各3个,相同颜色的球不加以区分,将此9个球排成一排共有____ 种不同的排法.(用数字作答)