单选题The wordstwo kinds in Line 4 mean the countries______.A which have snow either as yearly happening to celebrate or as rare weatherB which either have heavy snow or light snowC to which snow either causes problems or no problemsD which either have snow-

Which of the following is true?

Snow _____ is a big problem in some areas after the snow storm which lasts several days.

Which of the following is an intelligent repeater that is aware of the MAC addresses of the nodeson either side of the data link?（）

Passage1       Questions 1 to 5 are based on the following passage.       It's interesting that the arrival of snow has the effect on people in different countries.(76) For some countries it is an important happening to celebrate each year, while for others a catastrophe （灾害） or even a wonder.      But there are countries between these two kinds that normally expect snow some time over the winter months, but never receive snow regularly or in the same quantities every year.Britain is one of them, for which the arrival of snow quite simply creates problems.Within hours of the first snowfalls, however light, roads are blocked; trains and buses have to stop in the middle of the way.Normal communications are affected as well: telephone calls become difficult and the post immediately takes more time than usual.And almost within hours there are also certain shortages-bread, vegetables and other things-not because all these things can no longer be produced or sent to shops,but mainly because people are frightened and go out and store up with food and so on...just for fear that something bad should happen.      But why does snow have this effect? After all, the Swiss, the Austrians and the Canadians don't have such problems.It is simply because there is not enough planning and preparation.We need money to buy equipment to deal with snow and ice.To keep the roads clear, for example,requires snow-ploughs (扫雪机) and machines to spread salt.(77) The reason why a country like Britain does not buy snow-ploughs is that they are only used for a few days in any one year, and the money could be more useful in other things such as hospitals, education, helping the old, and so on.3 After a few hours' snowing there are often some shortages of food because______.

According to the writer, Britain is a country______.

Your vessel is off a lee shore in heavy weather and laboring. Which action should you take?（）.

Where events have rendered performance of the contract illegal either by English law or by the law of the country in which performance was to have taken place，the Charterer will（）from the liability to provide a cargo.

A vessel’s quarter is that section which is（）.

If the redelivery of a vessel is delayed by causes （），hire is payable at the charter rate until redelivery even though the market rate may have gone up or down.

A semisubmersible which will not remain upright and will assume a list either to port or starboard is likely to have（）.

Main engines as well as auxiliary engines operating on heavy fuel should have continuous on the lubricating oil, either according to the bypass or batch principles（）

A seaman may have all or part of his wages deposited by allotment to a bank or savings institution. Which of the following is NOT a requirement for this type of allotment? （）

Which statement describes a spanning-tree network that has converged?（）

Which one of the Cisco IOS commands can be used to verify that either the Cisco IOS image， theconfiguration files，or both have been properly backed up and secured？（）