A conscious victim who has suffered a blow to the head has symptoms that indicate the possibility of concussion. If the patient feels no indication of neck or spine injury，recommended treatment would include（）.

A “l(fā)iner” in riveted construction of a vessel is a(n)（）.

A “l(fā)oose” tow may cause all of the following EXCEPT（）.

A celestial body’s complete orbit around another body is（）.

A crew member has suffered frostbite to the toes of the right foot. Which is NOT an acceptable first aid measure?（）

A backlash below a lock is defined as a（）.

A continuous watertight bulkhead on a ship is normally also a(n)（）.

A tonnage tax is levied according to the（）.

A chart projection depicting the poles and a small area on either side of a connecting meridian，that is sometimes used for star charts，is the（）.

A “spring line” is（）.