单选题 As he wanted to watch the tennis final of the Olympic Games, he left a pile of dishes unwashed in the kitchen.
  • A. number
  • B. stack
  • C. group
  • D. crowd


【正确答案】 B
【答案解析】a numbel of：大量的；a stack of：一堆，和a pile of意思相同；a group of：一组、一群；a crowd of: 很多的。