- 搜標(biāo)題
- 搜題干
- 搜選項(xiàng)
單項(xiàng)選擇題
Production of mechanical foam by a portable in-line foam proportioner（）.
A.increases the size of foam bubbles formed
B.increases the rate of foam production
C.improves the extinguishing properties of foam
D.gives the nozzleman more freedom of movement，since it can be placed anywhere in the hose line
