( )是指通过某种方式对网络进行管理，使网络能正常高效地运行。
参考答案：网络管理
在实际操作中，组页眉和组页脚根据需要可以______。
--- Is it true that Mike refused an offer from Yale University yesterday?
--- Yeah, but I have no idea _______ he did it; that’s one of his favorite universities.
A．when
B．why
C．that
D．how
