一个工程项目要建成往往需要几年,建设过程涉及面广,而且会产生各种情况的变化,因此工程建设具有( )。
A.不可逆转性
B.整体性
C.固定性
D.许多因素带有不确定性
参考答案:D
Little _____ abut his own safety, though he was in great danger himself. [ ]
A. does he care
B. did he care
C. he cares
D. he cared
站内的道岔及股道由谁编号?