题目内容：

    Researchers in Japan have installed (安装) on a train a speaker that barks like a dog and snorts like a deer in order to prevent collisions with animals on the tracks.

The country has been troubled by a problem with trains colliding with deer on its railways. According to Japan’s transport ministry, there were 613 cases of train services delayed for at least 30 minutes resulting from collisions with deer and other wild animals in 2018-19.

Deer are attracted to railway lines because of a need for iron in their diets. They lick (舔) the rails to pick up iron filings caused by the action of wheels against tracks. This dietary need has led to a constant battle to keep the deer separate from the danger of a fast-moving train. In the past, flashing red lights and even lion faces have been unsuccessfully trialed in an attempt to keep deer off the tracks.

This new device has been invented by a team at the country’s Railway Technical Research Institute (RTRD). RTRI officials explain that deer have a habit of repeatedly snorting short, shrill sounds to warn other deer when they sense danger. The barking of the hunting dog, which drives deer to panic, strengthens the effect of the warning noise, according to the RTRI. When the deer hear a combination of a 3-second-long recording of a deer’s snort and 20 seconds of a barking dog, they panic and flee rapidly.

RTRI researchers say late-night tests, at times when deer are most frequently seen by railway tracks, have resulted in a 45 percent reduction of deer sighting. Future plans include still barking sites where deer are commonly seen, but the unpleasant noises will not be so loud in areas where people live beside the tracks.

1.Why are deer attracted to train tracks?

A.To get close to the passing trail. B.To get nutrition from train tracks.

C.To hunt for food near the train tracks. D.To gather together at night near railways.

2.What has been tried to solve the railway problem in Japan?

A.Robots. B.Hunting dogs.

C.Lion face paintings. D.Specially designed tracks.

3.What do we know about the speaker?

A.Its inventors drew inspiration from deer’s habit.

B.It will be put to use in areas where deer appear.

C.It will affect people who live beside the track.

D.It has decreased more than half of deer sighting.

4.What is the passage mainly about?

A.A dietary habit of deer.

B.A traffic problem caused by deer.

C.A battle between human and animals.

D.An invention designed to keep deer off the tracks.