卷门机的英文：
electric door roller

electric是什么意思：
adj. 电的；电动的；发电的；导电的；令人震惊的
n. 电；电气车辆；带电体

The atmosphere was electric.
气氛很热烈。

electric cartridge
带电体唱头

This electricity is then fed into the electricity grid system
然后,这一电流被输入电网系统。

door是什么意思：
n. 门，门户；途径

The door was unclosed.
门被人打开了。

This door is manual.
这个门是要用手操作的。

Who is knocking the door || Who is knocking || Who is at the door || Who is knocking at the door?
谁在敲门

roller是什么意思：
n. 滚筒，滚轴；巨浪

roller step bearing
滚柱止推轴承

You will need a lint roller.
你需要一个吸尘滚筒。

Be prepared for the possibility of a roller coaster.
为大涨大跌作好准备吧。