返回

科学素养与生活应用·英语30篇(9)

23 / 30
已读 0 / 30 课
How Automatic Doors 'See' People Coming In

How Automatic Doors 'See' People Coming In

自动门如何‘看见’走近的人并开启

  1. Automatic doors use invisible infrared beams near the entrance.
  2. When your body blocks the beam, the door knows someone is there.
  3. A small computer quickly checks and sends a signal to open.
  4. The door slides or swings open just wide enough for you.
  5. After a few seconds, it closes again quietly and safely.
  6. This smart sensing helps everyone, especially people with heavy bags.
上一页
/ 30
下一页