What is meant by the aging of a lake?

What is causing concern for the Taj Mahal?

Electrostatic Precipitator $(ESP)$:
$I.$ Is an electrical device to remove particulate matter present in the exhaust of thermal power plant.
$II.$ More than $99\, \%$ particulate matter can be removed by this method.
$III.$ $ESP$ has electrode wires and a stage of collecting plates.
Which of the statements given above are correct?

Which of the following pesticides does not inhibit cholinesterase?

Which of the following is a pollution-related disorder?

Which among the following is likely to have the highest levels of $D.D.T.$ depositions in its body?