A:2H2O⇌H3O++OH﹣
B:H2S⇌H++HS﹣
C:NaHS=Na++HS﹣
D:HCO3﹣=H++CO32﹣
Don't be ____ (暴露于) to the strong sunlight, which may damage your skin.
We must do as much as we ____to make our country better and more beautiful.