Catenary as applied to tow lines denotes the（）.

The condition where a ship on the end of a tow line is riding a wave crest at the same time as its tug rides a wave crest is known as riding in（）.

—Hurry up, or we’ll be late.—Take your time. it’s just ______ short distance from here to ______ cinema.

While your vessel is docked port side to a wharf，a sudden gale force wind causes the vessel’s stern lines to part. The stern begins to fall away from the dock，and no tugs are immediately available. Which measure(s) should you take FIRST?（）

为了保障海上移动通信的畅通，国际电信联盟将海上通信划分为四个优先级别，分别是（）。

If necessary to avoid collision or allow more time to（）the situation，a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion．

A tug is approaching a broken down steamer in moderately heavy weather preparing to take it in tow. In most cases the（）.

Before leaving port on an ocean tow，a tug captain should assure himself of all the following EXCEPT（）.

When a tug is pulling on a hawser at right angles to the ship，and the pilot wants to come ahead or astern on the ship’s engine，care must be taken that the pilot（）.

In astern towing，a tow span，also called the tow bar or towing arch，is used to（）.

If a vessel under tow starts jumping on its tow line，the most appropriate action to alleviate the condition is to（）.

When connecting the tow bridle to a tug, the end of the bridle is passed with a（）.