题目

Directions: For each blank in the followingpassage there are four words or phrases marked A, B, C and D. Fill in eachblank with the word or phrase that best fits the context.Why liars lie: What science tells us about deceptionWe all do it sometimes, even though we know it's wrong. But here'sthe problem with lying: research shows that the more you lie, the easier itgets, and the more likely you are to do it again. The dangerous thingabout lying is that people don't understand how the act changes us, saidDan Ariely, a behavioral psychologist at Duke.Psychologists have documented children lying a下列各组物质中，前者属于单质、后者属于氧化物的是（　　）A．生铁、硬水B．氮气、蒸馏水C．氧气、石油D．碳酸、空气