It was a long time before she ____ completely ____ with old people

问题描述:

It was a long time before she ____ completely ____ with old people
A,is ; used to working B,was ; used to working C,/ ; use to work D,did ; used to working

答案选B
意思是
很久她才完全习惯了与老人们一起工作.
过去时态,所以不能用A和C
D 结构不对的.