单选题 Revolutionary developments in China's astronomy took place in the 1960's.
  • A. commenced
  • B. occurred
  • C. were disputed
  • D. were exchanged


【正确答案】 B
【答案解析】take place和occur同义:发生、出现;commence:开始、着手;were disputed:被讨论、被争论;were exchanged:被交流、被交换。