A:y=cosx
B:y=xex
C:y=x3﹣x
D:y=lnx﹣x
为防止食品腐败变质,一般采取的保存方法有( )
①高温 ②低温 ③保持干燥 ④保持湿润 ⑤暴露空气中 ⑥隔绝空气.
As soon as he got home, it began to p____(倒;灌) outside.