A:Na2CO3是碳酸盐
B:Na2CO3是正盐
C:Na2CO3是钠盐
D:Na2CO3是碱
1╳8=8 2╳8=16 5╳8=40 10╳8=80
5╳8=____ 4╳8=____ 5╳8=____ 6╳8=____ 5╳8=____ 7╳8=____
2╳8=____ 3╳8=____ 10╳8=____ 9╳8=____ 10╳8=____ 8╳8=____
0╳8=____ 1╳8=____ 2╳8=____ 3╳8=____ 4╳8=____ 5╳8=____
6╳8=____ 7╳8=____ 8╳8=____ 9╳8=____ 10╳8=____