Mary _____ go to school by bike, but now she usually takes a school bus to school. [ ]

A. used to

B. had to

C. was afraid to

D. preferred to

现实中品牌生命周期有时表现为一种难以确定的趋势，有的品牌在成熟期之后不是进入衰退期，而是进入第二次成长期，如此反复，才进入衰退期，甚至有的品牌长盛不衰。