下列正确的是( )
A:﹣3xy2z•(﹣x2y)2=x5y4z
B:25=±5
C:x3﹣2x2y2+3y2是三次三项式
D:-12是整式
It was time for class. Mr. King asked all the children __________ down quietly.
若a>b,则下列不等式变形正确的是( )
old lady with white hair spoke English well at meeting.
新修订的食品安全法规定,禁止将剧毒、高毒农药用于蔬菜、瓜果、茶叶和中草药材等国家规定的农作物。这表明( )