单项选择题

Directions: In this section,there are 10 incomplete sentence& You are required to complete each one by deciding on the most appropriate word or words from the 4 choices marked. Then you should mark the corresponding letter on the Answer Sheet with a single line through the center. People ______ in summer in lakes around the city. But now there is no lake available.

A. used to swimming
B. was used to swimming
C. were used to swim
D. used to swim