单选题 After 1850, various states in the United States began to pass {{U}}compulsory{{/U}} school attendance laws.
  • A. harsh
  • B. diversified
  • C. mandatory
  • D. complicated
【正确答案】 C
【答案解析】[解析] compulsory意思是“强制的，义务的”，与mandatory(强制的)意思相近。harsh艰苦的，严酷的；diversified多种多样的，多元的；complicated复杂的，难懂的。