单选题 ______we admit that there are still some problems about NMET,we don't mean that it is of no use.
  • A. Until
  • B. While
  • C. As
  • D. Unless


【正确答案】 B
【答案解析】[解析] 连词while的意思是“当……的时候，虽然”，此处表示转折关系。