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:句意,在十五岁时,她放弃了上钢琴课,专心于她的学校功课。hold on坚持 call on 号召 put on穿上 concentrate on专心于,根据题意,故选D。