题目内容：

I’d be lying if I said a dog-like robot opening a door for another dog-like robot doesn’t creep me out. A full discussion of robot dogs is for another day, but for now, researchers studying the cognition（认知） and

welfare of real dogs have a less threatening view of dogs and technology, particularly when touchscreens are involved.

Like you, animals can learn to interact with the content displayed on touchscreens, and their touch reveals something about their choice, which in turn reveals something about their mind. Animals both on and off land can be trained to use touchscreens — from chimpanzees to dogs, cats, and even dolphins, among others. Touchscreen studies have explored how and what dogs categorize, their ability to learn by

exclusion（排除）, and how they discriminate between different images. An added bonus is that, once a dog

has mastered the touchscreen, humans can remove themselves from the study and can’t unconsciously give signals to the dog.

Researchers are now posing a new set of questions: are touchscreens beneficial to the user? Can touchscreens exercise the dog’s mind, in addition to serving as a window into it?

No better place to start than with older pet dogs, a group facing a unique set of challenges. Aging dogs can have reduced physical activity compared to their younger counterparts. Less attention is often given to their learning, training and other mental activities; after all, who hasn’t heard the wrong proverb, “You can’t teach an old dog new tricks.” But dog minds are not meant to be inactive. Instead, “studies point to the fact that aging seems to be slowed by mental and physical stimulation, and thus stopping these activities might actually lead to faster aging in dogs.”

Lisa Wallis and colleagues at the Senior Family Dog Project at ELTE University in Budapest are exploring the effects of touchscreens on dog physiological, behavioral, and cognitive well-being.

Their recent conference paper gives us a look at how dogs learn to use the touchscreen and the direction of future  research. Over the  course  of a number of sessions, dogs learned  that when they nose-touch a particular image on the screen, a food treat pops out. At first, only a single image appears on the screen. Once the dogs reliably learn to nose-touch the image, they move on to discrimination training where two images appear together and only one image is “correct.” Only two out of one hundred thirty dogs were unable to grasp the task, and three displayed frustration suggesting touchscreens are within the capacity of the majority of senior dogs.

Wallis and colleagues will continue investigating long-term effects of touchscreen use, but it seems promising. “The positive association to the touchscreen is so strong that on several occasions when the dog was alone (the trainer had stepped out to answer the phone), and the feeder failed, dogs continued to work on the touchscreen with no reward until the end of the session.” Owners, even those initially skeptical, were impressed by the strategies their dogs used. They also observed that dogs slept soundly upon returning home from touchscreen sessions, highlighting that mental activity can have some of the same effects as physical exercise.

Further studies will explore the effects of long-term touchscreen use on dog personality, activity levels, measures of well-being, and influence on the dog-human bond. Stay tuned.

1.What can we learn from the first two paragraphs?

A. Animals can decide the content shown on touchscreens.

B. Animals naturally have the ability to use touchscreens.

C. People can discriminate between dogs’ abilities by exclusion.

D. People can tell dogs’ needs through their touch on the screen.

2.By using the proverb in paragraph 4, the author intends to stress    .

A. aging dogs are too old to learn new skill

B. aging dogs experience a decline in energy

C. training younger dogs is more productive

D. training aging dogs is possible and beneficial

3.What is revealed by the research conducted by Lisa Wallis?

A. The dogs master the touchscreen use step by step.

B. Rewards are a must for dogs to finish the session

C. The dogs regard nose-touch as a form of physical exercise.

D. It remains to be seen whether it has a positive effect on dogs.

4.What does the passage mainly talk about?

A. How robot dogs have threatened the world.

B. How people establish better dog-human bonds.

C. How touchscreens can be employed to train dogs.

D. How long-held myths about dogs mislead people.