脊椎动物的共同特点是身体内都有由____组成的____.
⑴____ A. make B. late C. map D. male
⑵____ A. famous B. found C. shout D. ground
⑶____ A. worked B. called C. stayed D. lived
⑷____ A.mouth B.round C.group D.ground
⑸____ A.days B.bags C.pens D.maps
下列哪项的规律变化,不能反映出我国自然环境的差异显著( )