题目内容：

    A new wave of psychological research is pioneering Virtual Reality (VR) to treat medical conditions from social anxiety to Alzheimer's disease.

Riding a wave of interest in mental health tech, companies creating VR content for treatment are receiving a flood of attention and funding. And, while VR has been used successfully to treat post-traumatic stress disorder (PTSD) since the 1990s, these new programs address a much broader range of conditions. The library of Palo Alto-based Limbix, for instance, includes VR content designed to treat issues including alcohol addiction and teenage depression. Barcelona-based Psious offers treatments for eating disorders.

Today's VR content is primarily designed to aid exposure treatment, a treatment for anxiety disorders in which patients are exposed to the “threats” they're worried about in a safe, controlled environment, eventually learning that the “threats” are not actually very dangerous. For example, someone who fears heights might visit taller and taller buildings under the guidance of their doctor, while someone with PTSD might revisit painful memories.

VR allows doctors to create a safe and controlled environment inside a VR headset. It's a far safer, quicker and less expensive option. Using VR also gives doctors much more control over the intensity(强度)of their patients' experiences, which can lead to better treatment outcomes, said Stephane Bouchard, a professor at the University of Quebec. VR treatment patients can also do things they couldn't do in the real world. “In one of our studies, we asked patients who are afraid of heights to actually jump from a cliff,” Bouchard said.

However, not all VR treatment content is created equal. “Some companies show videos of VR environments that are incomplete, untested and definitely haven't been tried out by psychologists,” Bouchard said. Clearer rules and standards will make it easier for patients and doctors to identify products that work.

1.What problems can VR be used to treat according to the passage?

A.The fear of heights, blood pressure and eating disorders.

B.Social anxiety, PTSD and alcohol addiction.

C.Alzheimer's disease, heart attack and teenage depression.

D.Sleeping disorders, deafness and computer addiction.

2.What is the main idea of Para 4?

A.The benefits of using VR treatment. B.The principles of using V R treatment.

C.The side effects of using VR treatment. D.The causes of using VR treatment.

3.Which word can be used to describe the future of VR treatment?

A.Passive. B.Uncertain. C.Promising. D.Worrying.

4.What will be most probably discussed in the paragraph following the passage?

A.Wide use of VR treatment. B.Criteria of VR treatment.

C.Problems VR treatment are facing. D.Reasons why VR treatment standards are needed.