深圳成份股指数的基期值为 ( ) A．100 B．1000 C．10000

摩擦轮传动中，所需压紧力Q的大小与（）有关。

A．工作圆周力

B．径向力

C．法向压力

D．摩擦力

广告学研究的主要对象是（）

A、公益广告

B、商业广告

C、政府公告

D、社会广告

在建设工程实施过程中，( )的累计投资增加速度最快。

A．设计阶段
B．施工阶段
C．竣工验收阶段
D．保修阶段

电子商务框架结构中的网络基础设施层最重要的部分是（）

A.互联网

B.有线电视网

C.无线通信网

D.远程通信网

"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 (孤儿) in Africa!"
Sure, we should be grateful for every bite of food. Unfortunately, many people in the US take a few too many bites. Instead of saying "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 (肚子). 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 serve large portions to stand apart from competitors and to give the customers value. They prefer to have customers complain about too much food rather than too little.
Barbara Rolls, a nutrition professor at Pennsylvania State University, told USA Today, that restaurant portion sizes began to grow in the 1970s, the same time that the American waistline began to expand.
Health experts have tried to get many restaurants to serve smaller portions. Now, apparently, some customers are calling for this too. A restaurant industry trade magazine reported last month that 57 percent of more than 4 000 people surveyed believed restaurants serve portions that are too large; 23 percent had no opinion; 20 percent disagreed.
But a closer look at the survey indicates that many Americans who can’t afford fine dining still prefer large portions. Seventy 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.

According to the passage, working class Americans dining in restaurants ______.

A. eat less to save money
B. get less on their plate
C. want to get their money’s value back
D. do not care about their health