题目内容：

A study of 500，000 songs released（发行）in the UK between 1985 and 2015 showed that pop music has decreased in happiness and increased in sadness．

In a report published in the journal Royal Society Open Science，researchers at the University of California examined hundreds of thousands of songs and classified them by their mood．"‘Happiness’is going down，‘sadness’ is going up，and at the same time，the songs are becoming more ‘danceable’ and more ‘party-like，’"co-author Natalia L．Komarova told The Associated Press．

The study found songs in 2014 like "Stay With Me"by Sam Smith，"Whispers" by Passenger and "Unmissable" by Gorgon City to have a "low happiness" trend．However，tracks from 1985 like "Glory Days" by Bruce Springsteen，"Would I Lie To You？" by Eurythmics and "Freedom"by Wham had a high "happiness" trend．"The public seems to prefer happier songs， even though more and more unhappy songs are being released each year，" the researchers wrote．

Apart from the emotional trends，researcheis discovered that dance and pop were the most successful styles of music and that there was a "clear downward trend"，with the popularity oF rock beginning in the early 2000s．"So it looks like，while the overall mood is becoming less happy，people seem to want to forget it all and dance，" Komarova wrote in an email．

It was also found that the "maleness" of songs——the frequency of male singers in popular music——had decreased during the last 30 years "Successful songs are characterised by a larger percentage of female artists compared to all songs，"they Wrote．

This discovery appears at a time when the convcrsation around sex equality in the music industry is at its height，with more male artists and songwriters．

1.The researchers examined lots of songs to    ．

A. find songs for dance and party

B. choose songs for a journal

C. release more songs

D. know better about songs

2.Whose music style tends to bring you more happiness？

A. Natalia L．Komarova’s．    B. Sam Smith’s．

C. Gorgon City’s．    D. Bruce Springsteen’s．

3.What do we know about songs over the past three decades？

A. Rock became popular in the early 2000s．

B. Fewer unhappy songs come to light every year．

C. Male singers are better at perrorming pop music．

D. Female artists are less skilled in writing songs．

4.What can be a suitable title for the text？

A. Pop Music Is Getting Sadder

B. Music Calls for Sex Equality

C. Pop Music Has a Long History

D. Music Industry Is Going Down