真空计

例句：

1. 1. The vacuum cleaner is designed to suck up dust and dirt.
   吸尘器设计用来吸走灰尘和污垢。
2. 2.The vacuum cleaner is essential for cleaning the floor.
   吸尘器对于清洁地板来说是必不可少的。
3. 3. The vacuum cleaner was invented by a man named James Watt in 1769.
   真空吸尘器是由詹姆斯·瓦特在1769年发明的。