如图,在多面体ABCDEF中,已知平面ABCD是边长为3的正方形,EF∥AB,EF=32,且EF与平面ABCD的距离为2,则该多面体的体积为( )
(____) Ottawa is the capital city of Canada.
(____) The CN Tower is very tall.
(____) It has five yellow stars.
(____) They speak English and French.
(____) I live in China.
功率一定的拖拉机在深耕时的行驶速度比在公路上慢,这主要是为了( )
下列人类文明中延续时间最长的是( )