根据材料回答下列各题： 第三篇Eat Healthy “Clean your plate!”and“Be a member of the clean—plate club!”Just about every kid in the US has heard this from a parent or grandparent．Often，it’s accompanied by an appeal：“Just think about those starving orphans in Africa!”Sure，we should be grateful for every bite of food．Unfortunately， many people in the US take too many bites．Instead of stayin9“clean the plate”，perhaps we should save some food for tomorrow． According to news reports，US restaurants are partly to blame for the growing bellies．A waiter puts a plate of food in front of each customer，with two to four times the amount recommended by the government，according to a USA Today story．Americans traditionally associate quantity with value and most restaurants try to give them that．They prefer to have customers complain about too much food rather than too Iittle． Barbara R011s，a nutrition professor at Pennsylvania State University，told USA Today that restaurant Dortion sizes began to grow in the l970s，the same time that the American waistline began to expand． Health exDerts have tried to get many restaurants to serve smaller portions。Now， apparently， some customers are calling for this too．The restaurant industry trade magazine QSR reported last month that 57 percent of more than 4，000 people surveyed believe restaurants serve portions that are toolarge；23 percent had no opinion；20 percent disagreed．But a closer look at the survey indicates that manv Americans who can’t afford fine dining still prefer large portions．70 percent of those earning at least$150，000 per year prefer smaller portions；but only 45 percent of those earning less than$25，000 want smaller． It’S not that working class Americans don’t want to eat healthy．It’s just that，“after long hours at low—paying jobs，getting less on their plate hardly seems like a good deal．They live from paycheck to paycheck，happy to save a little money for next year’s Christmas presents． Parents in the United States tend to ask their children____________

A. not to waste food at meals
B. to save food for tomorrow
C. to wash the dishes clean
D. not to eat too much at meals