Stressful environment leads to unhealthy behaviors such as poor eating habits, which （ ）increase the risk of high blood pressure and heart disease.

A.in turn B.by chance C.by fortune D.in case

George Gallup, Jr ., the man who makes and（ ）his reputation （ ）knowing what Americans think, has brought all his polling strategies together to identify and analyze what he calls future forces.

I think that I committed a （ ）in asking her because she seemed very upset by my question.

I suggest we put the scheme into effect, for it is quite （ ）.

Oil companies in the U.S. are already beginning to feel the pressure. Refinery workers and petroleum-equipment-manufacturing employees are being （ ）.

We work to make money, but it's a （ ）that people who work hard and long often do not make the most money.