题目内容：

Children make quicker decisions to eat “tasty” food and reward centres in their brains light up after watching food commercials on television, compared to non­food commercials, a small study finds.

The researchers studied 23 children aged 8 to 14 who gave taste and health ratings for 60 food items. Afterwards, kids chose whether to “eat” or “not eat” each food item—without actually eating them—while undergoing brain scans. The scans measure changes in blood flow within the brain, which is thought to reflect the activity of brain cells.

While the kids were making their decisions, they were periodically shown TV commercials, some for fast food outlets and some for non­food businesses. Each set of commercials was followed by a set of 10 food choices.

In general, kids did not choose foods based on their health ratings and chose based on taste. But after watching a food commercial, taste seemed even more important to them and they made their choices faster. The area of the brain involved in reward valuation was more active during food decisions after watching food­related commercials than after non­food commercials.

“What we know from studies like this one is that food marketing has effects that go beyond simply increasing our liking or wanting of the product being advertised and actually affect our preferences for all foods in that category，” said Emma Boyland of the University of Liverpool.

“Parents should be aware of these results so that they can put limits on screen time that involves food advertising，” Bruce said. “They should also discuss with children the importance of thinking about commercials properly.” “But commercials are almost everywhere—television, online, radio, clothing. As adults, we have to work to teach children that a real healthy diet to support a full and active life contains very little of the food they see advertised，”Boyland said.

1.What were the children asked to do in the research?

A. Select favourite commercials.    B. Decide whether to eat or not to eat.

C. Observe the activity of brain cells.    D. List health ratings for some foods.

2.What happened to the children after watching food commercials?

A. The reward centres in their brains acted actively.

B. They made food choices based on health ratings.

C. They confused taste rating with health rating of the foods.

D. They had a good command of the methods to choose foods.

3.What can we infer from Boyland's words?

A. Food marketing should be strictly controlled.

B. It's hard to stop kids being exposed to food advertising.

C. Parents should forbid children to watch food commercials.

D. Children should be warned not to eat the advertised foods.

4.What is mainly talked about in the passage?

A. Children make decisions quickly when watching commercials.

B. Children's bad eating habits are mainly caused by food commercials.

C. Parents are concerned about the effect of food advertisements on kids.

D. Food advertisements can have a great effect on children's eating habits.