In the noisiest areas, mechanical ventilation will have to be installed in the exterior walls.

在大的地区，外墙必须安装机械通风装置。

26.the natural ventilation exhaust with damper to be proveded for control room.

有风门的自然通风排气装置装在控制间。

Our waste could be employed to fertilize the soil we grow our vegetables with, we'd just need to install some sort of ventilation.

我的废物可以用来给我种植蔬菜的土壤施肥，我要安装某种通风装置即可。

Modern teaching practices, the organization of desks in the classroom, poor classroom acoustics, and mechanical means of ventilation such as air-conditioning units all contribute to the number of children unable to comprehend the teacher's voice.

现代教学实践、教室课桌的布置、教室声学效果差以及空调等机械通风装置都导致儿童无法理解老师的声。