—The land in the southwest of China is in great need of .—Yes, it hasn't rained for a long time there.
A:people
B:food
C:water
已知x>0,由不等式x+1x>2,x2+2x>3,x3+3x>4可以推广为( )
如图,为了测量油桶内油面的高度,将一根细木棒从油桶小孔插入桶内,测得木棒插入部分AB的长为100cm,木棒上沾油部分DB的长为60cm,桶高AC为80cm,那么桶内油面CE的高度是( )cm。