题目内容：

    Cats may have “attachment (依恋) styles” that are similar to those of people. Contrary to cats' original reputation, most cats form deep, close relationships with their owners, researchers say.

A team of researchers studied the relationship between the owners and their kittens by a type of psychology experiment. They set up a room, which is bare except for a few toys. The team instructed each owner to sit in a circle outlined on the floor in the middle of the room and ignore his or her kitten for two minutes, not making eye contact or speaking unless the cat stepped inside the circle. Owners were allowed to interact (互动) with their pet if the cat entered the circle. Then, the owner left the cat alone in the room for two minutes, before re-entering and again sitting inside the circle.

The researchers tested 79 kittens and their owners and recorded each pair’s interactions on camera. Based on how the cat reacted to their owner’s return, the researchers believed 70 of the participants have attachment styles. The findings indicate that the attachment is probably a biological characteristic that may have evolved (进化) to improve survival.

To see if a particular kitten’s attachment could change with training, 39 of the kittens were arranged to join a special class and 31 weren’t. For six weeks of classes, the kittens that attended a special class socialized with other cats and unfamiliar adults, and learned how to sit or walk on leash (皮带). But when all of the kittens repeated the original experiment, very few switched attachment styles. It proves that the relationship formed between a human and a cat is stable over time, which means those first interactions are important, the researchers say.

The team hopes that understanding how cats bond with humans could help more stray (无主的) cats be adopted.

1.What is the original impression that cats make on people according to the text?

A.Indifferent. B.Close.

C.Kind. D.Lazy.

2.What is the second paragraph mainly about?

A.The process of the experiment.

B.The type of the experiment.

C.The achievements of the team.

D.The effect of the research.

3.What does the training classes suggest about a cat’s attachment to humans?

A.It changes easily.

B.It forms in six weeks.

C.It lasts for a long time.

D.It only shows to its owner.

4.From which is the text probably taken?

A.A biology textbook.

B.A research paper.

C.A health magazine.

D.A travel brochure