Oil spills can lead to ________________

(a)

increase of BOD

(b)

decrease of BOD

(c)

No change in BOD

(d)

None of the above

Incineration is the best method to dispose ____________

(a)

Agricultural waste

(b)

Sewage

(c)

Medical waste

(d)

Oil spills

DB is a standard abbreviation  used for the quantitative expression of

(a)

The density of bacteria in a medium

(b)

A particular pollutant

(c)

The dominant bacillus in a culture

(d)

A certain pesticide

The highest DDT concentration in aquatic food chain shall occur in

(a)

Seagull

(b)

Crab

(c)

Cell

(d)

Phytoplankton

The molecular formula for ozone is______

(a)

O₂

(b)

O₄

(c)

O₃

(d)

O₇