小题1:D
小题2:A
小题3:B
小题4:C
文章是关于世界各国学生的午餐。
小题1:猜测词义题。根据前一句Fast food and fried food sell the best among students，可知快餐和油炸食品会导致肥胖。D正确。
小题2:推断题。根据Untied States部分的School lunches must also provide at least one-third of the daily dietary allowances (定量) of protein, vitamin A, vitamin C, iron, calcium, and calories.
小题3:主旨大意题。通读全文可知文章是关于世界各国学生的午餐的。
小题4:推理题。根据第一段最后一句So what do students of your age eat for lunch at school?