单选题A warp end may be fitted for operating the derrick topping wire which adjusts the derrick （）.A lengthB slackC heightD rotation direction

Which of the following is NOT mentioned in this passage?

A.There may be oil vapor in the engine room

B.Pipes and fittings may be damaged if explosion takes place

C.The cooler should be drained

D.Bursting caps must be fitted

Which molten substance is poured into the basket of a wire rope socket being fitted to the end of a wire rope ________．

A.Babbitt

B.Bronze

C.Lead

D.Zinc

A、as

B、so as

C、duly

D、in order

If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably _____.

A.misalignment or worn main bearings

B.insufficient cylinder lubrication

C.defective or poorly fitted valves

D.All of the above

材料：

Every new crude oil tanker of 20000 tons deadweight and above shall be fitted with a cargo tank cleaning system using crude oil washing．The Administration shall undertake to ensure that the system fully complies with the requirements of MARPOL within one year after the tanker was first engaged in the trade of carrying crude oil or by the end of the third voyage carrying crude oil suitable for crude oil washing，whichever occurs later．Unless such oil tanker carries crude oil which is not suitable for crude oil washing，the oil tanker shall operate the system in accordance with the requirements of that Regulation．

Every existing crude oil tanker of 40000 tons deadweight and above shall be provided with segregated ballast tanks．Existing crude oil tankers may，in lieu of being provided with segregated ballast tanks，operate with a cargo tank cleaning procedure using crude oil washing unless the crude oil tanker is intended to carry crude oil which is not suitable for crude oil washing．

Existing crude oil tankers may，in lieu of being provided with segregated ballast tanks or operating with a cargo tank cleaning procedure using crude oil washing，operate with dedicated clean ballast tanks in accordance with the provision of Regulation 13A of this Annex for the following period：for crude oil tankers of 70 000 tons deadweight and above，until two years after the date of entry into force of the present Convention；and for crude oil tankers of 40000 tons deadweight and above but below 70 000 tons deadweight，until four years after the date of entry into force of the present Convention．

问题：

A new crude oil tanker of 30000 tons deadweight shall ________．

A.be fitted with crude oil washing system

B.operate dedicated clean ballast tanks

C.be fitted with segregated ballast tanks

D.be fitted with washing system other than crude oil washing system

Except________，the existing crude oil tankers may operate with any of the following installations．A.segregated ballast tanks

B.cargo tank cleaning procedure using crude oil washing

C.operate with dedicated clean ballast tanks

D.protection position

The latest date for an existing crude oil tanker of 60000 tons deadweight to install dedicated clean ballast tanks is ________．A.until two years after the date of entry into force of the present Convention

B.until four years after the date of entry into force of the present Convention

C.within one year after the tanker was first engaged in the trade of carrying crude oil

D.by the end of the third voyage carrying crude oil

It is inferred that ________．A.all oil tankers，both the newly built and existing ones，shall be fitted with a cargo tank cleaning system using crude oil washing

B.a new crude oil tanker of 20 000 tons deadweight and above may，in lieu of being provided with crude oil washing system，operate with segregated ballast tanks

C.a new crude oil tanker of 20 000 tons deadweight and above may，in lieu of being provided with crude oil washing system，operate with dedicated clean ballast tanks

D.a new crude oil tanker of 20 000 tons deadweight and above shall not be fitted with a cargo tank cleaning system using crude oil washing immediately after her entry in the trade of carrying crude oil

请帮忙给出每个问题的正确答案和分析，谢谢！

A band or collar on the top end of a boom to which the topping lift，midships guy，and outboard guys are secured，is called the ______.

A.collar band

B.guy band

C.pad eye collar

D.spider band