﹣11的相反数是( )
A:11
B:-11
C:111
D:-111
①实践基础上的理论创新能推动技术的进步
②矛盾的普遍性原理是关于事物矛盾问题的精髓
③拟态研究是具有主观能动性和社会历史性的活动
④迫求真理是认识的目的和归宿
下列说法中错误的是( )
He fell off the bike and hurt his leg yesterday._______, he had to stay at home for two or three months.