A:②→①→②→③→②
B:②→③→②→①
C:③→②→①→②
D:③→②→①
The girl__________ swim when she was only four years old. Isn't it amazing?
在一定条件下,让置于密闭容器中的下列各组物质充分反应后,再冷却至常温,密闭容器中的气态物质属于纯净物的是( )