题目内容：

    University of Pennsylvania researchers say that for the first time they have linked social media use to increases in depression and loneliness． The idea that social media is anything but social when it comes to mental health has been talked about for years， but not many studies have managed to actually link the two． To do that， Penn researchers， led by psychologist Melissa Hunt， designed a study that focused on WeChat， Snapchat and Instagram．

The study was conducted with 143 participants， who before they began， completed a mood survey and sent along photos of their battery screens， showing how often they were using their phones to access social media． "We set out to do a much more complete study which attempts to imitate real life．" Hunt said．

The study divided the participants into two groups： The first group was allowed to maintain their normal social media habits． The other， the control group， was restricted to 10 minutes per day on social media． The restrictions were put in place for three weeks and then the participants returned and were tested for outcomes such as fear of missing out， anxiety， depression and loneliness．

The results showed a very clear link between social media use and increased levels of depression and loneliness． "Using less social media than you normally do would lead to significant decreases in both depression and loneliness，" Hunt said．

Social media invites what Hunt calls "downward social comparison．" "When you're online， it can sometimes seem that everyone else is cooler and having more fun and included in more things and you're left out，" Hunt said． And that's just generally discouraging． "Every minute you spend online is a minute you are not doing your work or not meeting a friend for dinner or having a deep conversation with your roommate．" And these real life activities are the ones that can encourage self﹣esteem and self﹣worth， Hunt added．

"People are on their devices， and that's not going to change，" she said． But as in life， a bit of control goes a long way．

1.Before the study was conducted， the participants completed a survey to　   　．

A. imitate people's real life

B. link loneliness to depression

C. show their use of social media

D. prove social media is important

2.The results of the study showed using less social media would result in　   　．

A. people's fear of missing out

B. higher levels of depression

C. obvious relief in loneliness

D. lower levels of happiness

3.In Hunt's opinion， which activity benefits more to mental health？

A. Hiking out with friends．

B. Making comparison with others．

C. Playing computer games in spare time．

D. Logging onto social media and having fun．

4.Which can be the best title of the passage？

A. A Study on Social Media．

B. How to Improve Mental Health．

C. People Addicted to Social Media．

D. Social Media Influences Mental Health．