krisraam

A. Many new houses are built with air-filtration systems that remove from the house pollutants that are generated indoors. This one is irrelevant. B.The easing of standards for smokestack emissions has led to an increase in air-pollution levels in homes This might be true for both new and old houses. C.New houses built in secluded rural areas are relatively free of air pollutants This one strengthens. (D) Warm-weather conditions tend to slow down the movement of air, thus keeping pollution trapped near its source. This is true for both new and old houses (E) Pressboard, an inexpensive new plywood substitute now often used in the construction of houses, emits the pollutant formaldehyde into the house This is right because it gives a alternate reason for the cause. Thanks raama

In Method 2 No of ways of arranging CIII = 4!/3! = 4 Thanks raama

Imo A

Imo A

For Option D. Just because sound of boat travels much further under water doesn't mean manattes will be able to sense. So Answer is E

Imo D

Imo D

Imo A