The sound of the birds happy memories of my childhood holidays.
A. called up
B. called for
C. called on
D. called in
网友回答
(答案→)A. called up
B. called for
C. called on
D. called in
解析：考查动词短语：A. called up唤起，B. called for需要，要求，C. called on 号召，D. called in召集，句意是：小鸟的声音唤起了我童年假日的快乐记忆。选A。