①中华文化对别国的渗透能力增强
②中国文化被世界各国所认同
③各民族都有自己的文化个性和特征
④各民族文化是世界文化不可缺少的
A:①②
B:①③
C:②③
D:③④
In April, the weather in some places in Shanxi was really changeable. People still remember they have _______ four seasons in a week.
分解因式:a2+3ab=____