单选题 They hold a party to observe their 30th maRRiage anniversary.
  • A. watch
  • B. understand
  • C. explain
  • D. celebrate


【正确答案】 D
【答案解析】本题考查的是常见的动词。observe观察，遵守，庆祝；watch观察，看；understand明白，理解；explain解释；celebrate庆祝。所以正确答案为D。