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單項選擇題

Disinfector in the sewage biological treatment plant usually is （）

A.chlorine water
B.ozone
C.hypo-calcium chloride
D.calcium oxide

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單項選擇題

Before marine sewage treatment plant works （） should be filled with fresh water.

A.deposition chamber
B.oxidation pool
C.disinfection chamber
D.all chamber

單項選擇題

When does auxiliary burner of rotary nozzle incinerator begin to work? （）
Ⅰ.hen igniting
Ⅱ.he sludge for dealing with is too much
Ⅲ.efore stopping incinerator

A.Ⅰ+Ⅱ
B.Ⅰ+Ⅲ
C.Ⅱ+Ⅲ
D.Ⅰ+Ⅱ+Ⅲ

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