Scientists from Imperial College London have found that using virtual reality（VR）headsets can reduce sensitivity to pain，by immersing（沉浸）people in icy Arctic scenery.In a study published in Pain Reports，a team from Imperial used VR video to reduce people's sensitivity to ongoing pain and sharp shooting pain.
   According to the researchers，the findings add to the growing evidence for the potential of VR technology to help patients with long-term pain.Beyond the distracting effect，they think VR may actually cause the body's own inbuilt pain-fighting systems to start working.
   Dr Sam Hughes，the first author on the paper，said "Our work suggests that VR may be getting involved in processes in the key parts of our inbuilt pain-fighting systems and are helpful in regulating the spread of increased sensitivity to pain."
   To test their theory，researchers applied a cream containing capsaicin（辣椒素）-the chemical that makes your mouth bum-to 15 healthy volunteers.The capsaicin makes the skin more sensitive to painful stimuli（刺激）like a very small electric shock.
   In the first trial，participants were then asked to rate the pain caused by the capsaicin cream on a scale of 0-100（from 'no pain' to 'worst pain possible'）while either watching a VR scene of Arctic exploration through a headset，or looking at a still image of an Arctic scene on a monitor.Under the same conditions，they were also asked to say when a stimulus applied directly to the skin area is considered as painful.
   The team found that ongoing pain was reduced following VR immersion，and that sensitivity to painful stimuli was also reduced.However，the same effect was not seen in people who looked at still images of the polar environment.
   They explain that while the findings made at the beginning are encouraging，the study is limited by the small number of healthy participants，without long-term pain.However，the researchers believe VR could hold a bright future to treat patients with long-term pain who have poor inbuilt pain fighting systems.

（1）How can VR possibly help long-term pain sufferers？

C

C

A．By controlling the spread of pain sensitivity.
B．By slowing down their brains' reaction to pain.
C．By making their pain-fighting systems function.
D．By drawing their attention to fighting pain.
（2）Which step comes first in their theory testing？

A

A

A．Applying capsaicin cream to the skin.
B．Looking at pictures on a computer screen.
C．Making a capsaicin cream.
D．Putting on virtual reality headsets.
（3）What conclusion can be drawn from the trial？

D

D

A．Healthy people were less sensitive to VR than pain sufferers.
B．Capsaicin cream brought people more pain than electronic stimulus.
C．Still images helped to ease people's pain.
D．VR immersion was the key factor in pain reduction.
（4）What does the last paragraph imply？

C

C

A．VR treatment can be applied in other medical fields.
B．The trial only has an effect on short-term pain patient.
C．The team feels confident about future VR treatment.
D．The researchers will work on the side effect of VR.