Steps must be taken _____ this kind of disaster will never happen again.

A．because

B．even if

C．so that

D．as

设置幻灯片备注页的页眉为"美好"的步骤是（）

A."视图"→"页面设置"→"备注和讲义"→"页眉"→输入"美好"

B."视图"→"页眉页脚"→"幻灯片"→"页眉"→输入"美好"

C."视图"→"页眉页脚"→"备注和讲义"→"页眉"→输入"美好"

D."视图"→"页面设置"→"幻灯片大小"→"页眉"→输入"美好"