按红、白、黑、蓝、绿、紫六个玻璃球放在布袋里,每次只能摸出两个球,一共有______种拿法.
5+4+3+2+1=15(种),
答:一共有15种拿法,
故答案为:15.
Betty arrived Shanghai the evening of June 1st. [ ]
A.at, in
B.at, on
C.in, in
D.in, on
列举主流动画创作法则中英雄法则的几种观众心理状态。