单选题The ship’s draught forward is slightly deeper than the draught aft．This condition is called（）in shipping terms.A trim by the headB trim by the sternC even keelD drafts different

All the following is true except that ______．

A.in many places a counter current flows in opposition to the main current close to the bank

B.current can vary with depth of water and large deep draught ships can experience different current effects at differing parts of the hull tend to turn to the wind

C.as speed is reduced，the increased proportion of the ship's vector which is attributable to current will set the ship close to obstructions

D.when close to the berth in a head current，there is a danger that flow inshore of the ship becomes restricted and the ship is subject to interactive forces

The velocity of the apparent wind can be more than the true wind，and come from the same direction，if certain conditions are present．One condition is that the ______．

A.Ship's speed must be less than the true wind velocity

B.True wind must be from dead astern

C.True wind velocity must be faster than the ship's speed

D.True wind must be from dead ahead

In moving forward, a ship imparts forward motion to the water at the stems, this is known as _____.

A.the speed of the vessel

B.the speed of the propeller

C.the wake

D.the wake fraction

A tug would NOT assist a ship to steer if the tug is made up to the large vessel ______.

A.by a tow line ahead of the vessel

B.forward on either bow of the vessel

C.approximately amidships of the vessel

D.on the vessel’s quarter

______ is not an item of the communication between the ship and shore．

A.agreed procedure to STOP cargo operations

B.Personnel responsible for terminal cargo operations

C.agreed procedure for draught checking

D.agreement between the ship's Master and the terminal representative

材料：

Every new crude oil tanker of 20000 tons deadweight and above and every new product carrier of 30000 tons deadweight and above shall be provided with segregated ballast tanks．The capacity of the segregated ballast tanks shall be so determined that the ship may operate safely on ballast voyages without recourse to the use of cargo tanks for water ballast．

In all cases，however，the capacity of segregated ballast tanks shall be at least such that，in any ballast condition at any part of the voyage，including the conditions consisting of lightweight plus segregated ballast only，the ship’s draughts and trim can meet each of the following requirements：

（a）The moulded draught amidships（dm）meters（without taking into account any ship&39;s deformation）shall not be less than dm = 2.0 + 0.02L；

（b）The draughts at the forward and after perpendiculars shall correspond to those determined by the draught amidships（dm）as specified in sub-paragraph（a）of this paragraph，in association with the trim by the stern of not greater than 0.015L；

and（c）In any case the draught at the after perpendicular shall not be less than that which is necessary to obtain full immersion of the propeller．

In no case shall ballast water be carried in cargo tanks，except on those rare voyages when weather conditions are so severe that，in the opinion of the master，it is necessary to carry additional ballast water in cargo tanks for the safety of the ship，or，in exceptional cases where the particular character of the operation of an oil tanker renders it necessary to carry ballast water in excess of the quantity required，provided that such operation of the oil tanker falls under the category of exceptional cases as established by the Organization．

问题：

According to this passage，it is inferred that ________．

A.the crude oil is more pollutive than the product

B.the crude oil is less pollutive than the product

C.the crude oil and the product are equally pollutive

D.it can not tell whether the crude oil or the product is more pollutive

Ballast water ________ carried in cargo tanks on board of oil tankers．A.can be

B.can not be

C.can not，absolutely，be

D.can，only in rare or exceptional cases，be

This passage is most likely extracted from ________．A.Guide to Port Entry

B.Notices to Mariners

C.SOLAS

D.MARPOL

Assuming the length of a crude oil tanker is 200m，her max aft draft corresponding to her displacement of lightweight plus segregated ballast only should be ________．A.3m

B.4.5m

C.6m

D.7.5m

请帮忙给出每个问题的正确答案和分析，谢谢！

Owing to the deep draught of the ship，she has to go alongside by the time of______．

A.spring tide

B.flood tide

C.ebb tide

D.slack water

In practice, it is usual for ship to be loaded _____ to improve the vessel’s movement through the water.

A.a little deeper aft

B.a little deeper forward

C.at the same draught between fore and aft

D.a balance between two sides