The main bearing shells are made of steel with a lining of bearing metal which may be white metal, copper-lead or aluminum-tin alloy What is the meaning of “which” in the sentence above?（）

Main bearings are required to support the crankshaft at each （）.

Generally speaking, suction heads require to be （） for high speed or large capacities than for low speed or small capacities.

（） provides the head or pressure to supply the domestic water where required.

All towing vessels of 26 feet or longer while navigating are required to carry which item? （）

All offers（）require payment or private information before giving an award are bogus.

The goal, which they are unlikely to live to see , is tocure, prevent or manage all diseasesin the next 80or so years.

Whenever visible traces of oil are observed on or below the surface of the water in the immediate vicinity of ship or its wake，Governments of Parties to the Convention should，to the extent they are reasonably able to do so，promptly（）the facts bearing on the issue of whether there has been a violation of the provisions of this Regulation or Regulation 10 of this Annex of MARPOL 73/78.

Effects which are dutiable or subject to prohibitions or restrictions should be declared in （）.

（）are liable to be stoten, pilfered or may damaged due to improper handing or stowage.

（） system is arranged to ensure that water can be drawn from any tank or the sea and discharged to any other tank or the sea as required to trim the vessel.

Excessive clearances in the main or crank-pin bearings will sometimes be indicated by （） before any bearing knock is heard.