下列词语中，没有错别字的一组是（  ）

A．安分黄粱梦出类拔萃明枪易躲，暗剑难防

B．部署辩护人鸦鹊无声为山九仞，功亏一篑

C．青睐爆发户永葆青春众口铄金，积毁销骨

D．喝彩嘉奖令老生常谈失之东隅，收之桑榆

 单项选择。

There ______ a tree in front of the classroom last year, but there ______ now. [ ]

A. is, isn't

B. isn't, is

C. was, wasn't

D. was, isn't