【题目】There _____ a tall tree in front of the building over there, didn’t there?
A. was B. would be
C. must be D. used to be
在线课程【答案】D
【解析】考查谓语动词的时态。句意：---那边的大楼前面曾经有一棵大树，是吗？如果是A的话，附加成份为wasn’t there? 如果是C项的，附加成分为isn’t there? 根据最后的附加问句didn’t there？可判断用used to be，故选D项。