问题 问答题 论述题

怎样实现长调车进路由远至近顺序开放?

答案

参考答案:在长调车进路中,为了实现由远至近顺序开放调车信号的要求,电路上是通过KJ电路来实现的。

1.在KJ3-4线圈的励磁电路中,负极性电源是通过JXJ的后接点接入的。在长调车进路未全部选出以前,因为JXJ不失磁落下,所以KJ不能励磁吸起,信号不能开放。

2.在KJ3-4线圈的电路中,正极性电源是通过同方向第二架调车信号机的AJ后接点和FKJ后接点条件接入的,由于第二架信号机还未开放,FKJ在吸起,因此在第二架调车信号机开放以前,KJ不能励磁吸起,只有在第二架调车信号机开放以后,FKJ落下,第一架调车信号机的KJ才能励磁吸起,信号才能开放,从而实现长调车进路由远至近顺序开放。

多项选择题
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Bears and humans often meet in National Parks. Although campers and hikers are warned not to feed the bears, many people ignore these warnings and feed the beasts anyway. When bears are used to people’s food, problems soon arise.

Bears like to eat a large variety of things, both meat and vegetable. Without human assistance, bears live nicely on roots, twigs, leaves of trees, insects and small animals. With people around, the bears’ tastes quickly expand to include sandwiches, hot dogs, hamburgers, and anything else they can temp humans into giving up.

Bears often develop clever strategies for getting people to let go their food supplies. More often than not, an unsuspecting hiker has taken off his or her pack for a rest only to have a bear charge out of the woods, grab the pack and quickly disappear into the underbrush with it. Hanging the pack on a tree branch won’t help. Bears have been known to climb up, jump off, and catch the pack on the way down. One mother bear stretched up with her baby on her shoulders to reach a pack stored on a pole. Many bears threaten people into giving up their supplies. Although a bear is unlikely to attack a person and would probably run away if screamed at, few people are willing to do so. Most people drop the pack and run the other way. This, of course, delights the bear. In some places, the Park Service installed some metal barrels with lids to help campers keep their supplies safe from bears. Although the bears were unable to open these containers, the effort was less than successful. Most campers, unable to tell the metal drums from rubbish cans, never used them for the intended purpose.

小题1:Feeding bears on people’s food         .

A.brings the people a lot of fun

B.can cause problems

C.often causes injuries and deaths

D.helps bears survive小题2:If people had never fed bears, the bears        .

A.might be satisfied with what they had originally

B.would have starved long before

C.wouldn’t have enough food supply

D.would have hunted for other kind of food小题3:Which of the following is TRUE?

A.If fed on sandwiches and hot dogs, the bears would no longer eat roots, twigs and insects .

B.It’s likely that bears would hurt people if the people didn’t give up their food.

C.Most people would frighten away the bears that would temp their food.

D.Seeing a pack, the bear would quickly snatch it and run away with it.小题4:Bear-proof containers didn’t work because         .

A.bears were clever enough to get the food in them

B.they were left open in the open air

C.people were not sure of their use

D.they were once used as rubbish cans