公告的特点主要有（）
A、制发机关的限制性
B、发布事项的重要性
C、发布范围的广泛性
D、发布方式的单一性
参考答案：A, B, C, D
When moored with a Mediterranean moor，the ship should be secured to the pier by having（）.
A.a stern line and two quarter lines crossing under the stern
B.a stern line，2 bow lines，and 2 quarter lines leading aft to the pier
C.all regular lines leading to the pier in opposition to the anchor
D.two bow lines and two midship lines leading aft to the pier
