对正处在生长发育时期的青少年来说，一日三餐都很重要．根据合理营养的要求，在每日摄取的总能量中，哪餐摄入的能量应最多（　　）

阅读理解

    It was once common to regard Britain as a society with class distinction. Each class had unique characteristics.

    In recent years, many writers have begun to speak of the 'decline of class ' and 'classless society ' in Britain. And in modern day consumer society everyone is considered to be middle class.

    But pronouncing the death of class is too early. A recent wide-ranging study of pubic opinion found 90 percent of people still placing themselves in a particular class; 73 percent agreeed that class was still a vital part of British society.; and 52 percent thought there were still sharp class differences. Thus, class may not be culturally and politically obvious, yet it remains an imprtant part of British society. Britain seems to have a love of stratification.

    One unchanging aspect of a British person's class position is accent. The words a person speaks tell her or his class. A study of British accents during the 1970s found that a voice sounding like a BBC newsreader was viewed as the most attractive voice. Most people said this accent sounds 'educated ' and 'soft '. The accents placed at the bottom in this study, on the other hand, were regional(地区的) city accents. These accents were seen as 'common ' and 'ugly '. However, a similar study of British accents in the US turned these results upside down and placed some regional accents as the most attractive and BBC English as the least. This suggests that British attitudes towards accent have deep roots and are based on class prejudice.

    In recent years, however, young upper midder-class people in London, have begun to adopt some regional accents, in order to hide their class origins. This is an indication of class becoming unnoticed. However, the 1995 pop song ' Common People ' puts forward the view that though a middle-class person may ' want to live like common people ' they can never appreciate the reality of a working class life.