差错原因被隐瞒属于以下哪种情况的特点（）
A、失效的安全文化
B、官僚的安全文化
C、积极的安全文化
D、没有安全文化
参考答案：A
—Where is Tom ?
—Well , he __________ you __________ here. Otherwise he would come down right now.
A．didn’t know ; were
B．hasn’t known ; are
C．doesn’t know ; are
D．hadn’t known ; were
某飞行员，男性，30岁。将要执行为期一年的夜间飞行任务。
应多吃的食物是（）。
A.红薯
B.韭菜
C.干豆类
D.啤酒
E.胡萝卜
