A:图①所示实验可比较硫、碳、硅三种元素的非金属性强弱
B:用图②所示实验装置排空气法收集CO2气体
C:图③表示可逆反应CO(g)+H2O(g) CO2(g)+H2(g)的ΔH大于0
D:图④装置可以用来除去SO2中的HCl
When will you return to your hometown?
__________.
A traffic accident happened this morning. ____ (luck), no one was badly hurt.
若点A(-2,n)在x轴上,则B(n-1,n+1)在( )
叶片的结构由____、____和____三部分组成。