DME安装在航路上时，其系统延时一般固定为50微秒。
参考答案：对
— I have great ________ in finishing the work by myself. Could you help me?
— No problem.
A．fun
B．success
C．advice
D．difficulty
四川成都平原出土的“三星堆”青铜文化举世闻名。[ ]
