A:last two relaxing
B:two last relaxing
C:relaxing last two
D:last relaxing two
如果a,b,c满足c<b<a且ac<0,那么下列选项中不一定成立的是( )
9×52=____.
读诗《青松》写出诗句的意思。
①要知松高洁:
②大雪压青松: