A:②③①
B:②①③
C:③①②
D:①③②
①装药品 ②检查装置气密性 ③排水法收集气体 ④固体装置 ⑤加热 ⑥把导管从水槽中取出 ⑦停止加热.
Be d____ to do what you like, and you will make it.