A:①②③④
B:①③④
C:②③④
D:①④
Did Mike have ______ accident when he was eight?( )
以粟为主要粮食作物,过着原始农耕生活的居民是( )
3____3=9 4____4=8 6____4=10
3____1=2 2____2=4 4____3=1