• 2022-05-29
    The air inside a house or office building often has higher concentrations of contaminants ____ heavily polluted outside air.
    A: than does
    B: more
    C: as some that are
    D: like of
  • A

    内容

    • 0

      词汇与结构 Warm air is less dense than cool air, and _____ air is less dense than dry air.

    • 1

      The basic principle behind the total structure ventilation design is to use inside air to sweep up through a building to clear and remove the dust-laden air.

    • 2

      Growing evidence indicates air within homes and other buildings can be more seriously polluted than industrialized cities.

    • 3

      The basic principle behind the total structure ventilation design is to use inside air to sweep up through a building to clear and remove the dust-laden air. A: 正确 B: 错误

    • 4

      The pressure of pilot air is usually () than that of starting air.