下列选项中属于宪法规定的内容的是( ) ①国家的根本制度 ②公民的基本权利和义务 ③什么是犯罪 ④国旗、国徽、国歌、首都 ⑤国家机构和组织活动原则
A:①②④⑤
B:③④⑤
C:①②③④⑤
D:①②③⑤
已知A=1x+1,B=x-1x2+2x-1,求A与B的差;当x≠﹣1时,比较A与B的大小.
—Why don't you go out to play, Rose?
—I'm afraid I can't. I have much homework _________.
用向上排空气法收集氧气时,验满的方法是( )
Thanks for your invitation, but I'm so sorry I can't go. I need to _________ my baby at home.