单项选择题A．The amount of money. B．Family size. C．The nice neighbor. D．One’s social position.

单项选择题A．Men blush more than women. B．Children blush easily. C．People blush consciously. D．It is more or less a learned behavior.

单项选择题A．Because the police could not see them in the dark. B．Because many of them were armed with guns. C．Because there were not enough policemen to catch them all. D．Because they were hidden inside big buildings.

单项选择题A．It was by continuous exploitation of the environment. B．It was largely by chance. C．It was because of houseflies. D．It was by chance initially and by cleverness now.

单项选择题A．They suffer from mental pains. B．They start doing something in an active way. C．They become uninterested in class activities. D．They may grow up to be passive watchers.

单项选择题A．They have three children already. B．Cathy wishes to have a baby, but Tom doesn’t. C．They will start a family as soon as they get married. D．They don’t want children for the time being.

单项选择题A．To look at the audience directly. B．To look at something else in the room. C．To be better prepared before presentation. D．To ask psychologists for help.

单项选择题A．We need it to decorate our bodies. B．It is our second need. C．We need it to cover our bodies. D．Weather is changing all the time.

单项选择题A．She couldn’t wait her bus home. B．She spent her time shopping. C．She got interested in what she is reading. D．She didn’t wake up in time.

单项选择题A．Why species don’t avoid extinction by adapting. B．Why species become extinct at the rate they do. C．Why humans aren’t extinct. D．How many species aren’t extinct.