预防接种的时间，一般要求（）。
A.在夏季
B.在冬季
C.在秋季
D.在流行季节前3个月～6个月
E.在流行季节前1个月～2个月
参考答案：E
系统设计报告的主要作用是作为系统______的依据。
Was it at the school ______ was named after a hero ______ he spent his childhood?
A．which; that
B．where; that
C．that; where
D．which; where
