At the age of fifteen she gave up taking piano lessons to her school work.A. hold onB. c

问题补充：

At the age of fifteen she gave up taking piano lessons to her school work.

A. hold on

B. call on

C. put on

D. concentrate on

答案：

A. hold on

B. call on

C. put on

(答案→)D. concentrate on

解析：考查词组：A. hold on 别挂断B. call on号召C. put on穿上D. concentrate on专注于，句意：在15岁的时候，她放弃上钢琴课，专心学习。选D。