——The number of the tigers is getting __________. ——I agree _______ you.
A:more and more , to
B:smaller and smaller, to
C:smaller and smaller, with
D:more and more ,with
我国某河流:水量较丰富,每年5月和8月前后有两次汛期,含沙量少,有4﹣5个月的结冰期.该河流位于( )
若a2=3,b =2,且ab<0,则a-b=____ .