A:She's glad to hear that.
B:She's sad to hear that.
C:She's sorry to hear that.
“稻花香里说丰年,听取蛙声一片”,这里的蛙声是谁发出的?有何意义?( )
①生产发展 ②阶级产生 ③贫富分化 ④私有财产出现
下列函数中,是二次函数的是( )