问题补充：
Her son coke, but now he milk.
A. used to drink; is used to drinking
B. used to drinking; drinks
C. is used to drinking; used to drink
D. is used to drink; is drinking
答案：
(答案→)A. used to drink; is used to drinking
B. used to drinking; drinks
C. is used to drinking; used to drink
D. is used to drink; is drinking
解析：used to do sth, 表示过去常常做某事。Be used to doing sth, 表示习惯于做某事。句意：她的儿子过去常常喝可口可乐，但是现在他习惯于喝牛奶。故选A。
