【题目】Our school appeals to the students to _________ at least an hour every day to take exercise in order to raise learning efficiency．
A．set aside B．pick out
C．take up D．keep back
在线课程【答案】A
【解析】
试题分析：考查短语。句意：我们学校呼吁学生们留出最少一个小时时间来锻炼为了提高学习效率。 A．set aside 留出；B．pick out 挑出；C．take up占据；D．keep back回来。根据句意知选A。