It’s necessary for you to at least an hour each day to learn the new vocabulary.
A. set off
B. set out
C. set aside
D. set down
网友回答
A. set off
B. set out
(答案→)C. set aside
D. set down
解析：句意:你每天留出一个小时的时间来学习生词。set off出发；set out出发，开始；set aside留出；set down 记下。根据句意故选C。