The main purpose of the first 3 paragraphs of the passage is to ______. A: prove that contaminants are harmful to health B: show that contaminants could affect the future generations C: describe some experiments made by toxicologists D: urge that pesticides should be abandoned

The air inside .a house on office building often has more contaminants（）the heavily polluted air outside. A: than does B: as C: as some that are D: than that of

Oil<br/>filters, if regularly serviced, can remove solid contaminants from<br/>crankcase oil, but chemical reactions may form liquids that are<br/>corrosive and damaging. ( )

The air inside a house or office building often has higher concentrations of contaminants ____ heavily polluted outside air. A: than does B: more C: as some that are D: like of

The air inside a house or office building often has higher concentrations of contaminants ( ) heavily polluted air outside. A: like of B: more C: than do D: than does

Lube oil filters remove contaminants from oil more efficient if the oil being filtered is_______. A: heated to reduce viscosity B: cooled to increase viscosity C: pumped rapidly through the filte D: pumped through the filter under high pressure

One function provided by a hydraulic accumulator is to______. A: provide<br/>an area where air can separate from the oil B: provide<br/>an area to separate solid contaminants from the oil C: act<br/>as an oil and water separator D: absorb<br/>shocks occurring in the system