A:18
B:12
C:6
D:4
已知:ZnO+H2SO4=ZnSO4+H2O CuO+H2SO4=CuSO4+H2O
We often meet together and discuss ________.
墨水在温水中比在冷水中扩散快,说明分子运动的快慢与____有关.
Tom ________ with his aunt and uncle because his parents have gone abroad for a holiday.