A. Made to stay in the same class. B. Obliged to study in the lower class. C. Prevented from advancing. D. Concentrated on their studies. 参考答案:C 答案解析:[解析] 语义理解题。根据文章前两句中间的过渡词on the contrary可知,两句表达的意思相反。若明白后句的意思就不难推断出该词组的意思。第二句意思是:学生们的知识和经验因合班教学得到充实。由