An air conditioner because the teacher is setting the temperature and air conditioners always makes the class cold.
Answer: Are you in 6th grade? :0 i just learned ancient civilizations, it's A, by the way
Explanation: They wanted durable currencies that wouldn't break because it would be difficult to start trade and purchase the goods, and if they did break, they'd just be losing money, technically.
Answer: Demand characteristics.
Explanation:
Demand characteristics are the traits shown by participant of the research and experiment in which they behave according to the expectancy of researcher or experiment so that aim of the research can be accomplished .This creates biasness in research process and decrease validity of the experiment.
According to the question, John's positive reply to the situation where someone need helps if his/her car is broken displays the impact of demand characteristics .In actuality , he would probably not help the person by stopping and he just answered in positive manner to support the study.Thus, the reply is biased.