People have all turned to sad music to make themselves feel better at some point in their lives, ____why does the music with double or even triple sadness help drag people out of low spirits?

    A new study throws light on what's going on inside people's brains when they match their music to their feelings, and it looks as if sad music can be enjoyable, rather than____(simple) depressing. Music of this sort can arouse positive memories in people's life , thus ____(lift)their mood.

    Psychologist Adrian North from Curtin University in Australia says there____(existence) two groups of possible explanations for why people enjoy listening to sad music like this---one from social psychology, and the other from cognitive neuroscience(神经学).

    ____terms of social psychology, one idea about this is that people will feel____(good) about themselves if they focus on someone who's doing even worse. Everything's going to be okay, because this person is having ____even worse day than they are.

    Another idea from social psychology is that people like to listen to the very music____shows their present life circumstances, because this kind of music makes them feel they are understood. With their emotions____(share), they definitely get a certain amount of comfort.

    So, the____(conclude) again—sad music does cheer people up, and it works far better than happy music, in most cases.

It's 8:00. It's time to read books.

____。

    Everyone tries to get to school on time. But when bad weather gives you trouble, can you still make it before the bell rings?
In northern China during spring, big sandstorms often make trouble for students and everyone else. When the sky is dark with sand, buses and cars all move much more slowly. Sometimes, people can't even see for 20 metres.
    Sandstorms usually happen in spring. This year, sandstorms started in late March. They have happened in more than 10 provinces (省)  in northern China this year. More than 70 million people have had problems in those places because of the sandstorms.
    People in southern China don't have to worry about this kind of bad weather. Most of the sand comes from Gansu and Inner Mongolia（内蒙古）. In northern China, lots of places have few trees and don't get much rain. People there have been cutting down too many trees. When there aren't many trees, the ground can't keep enough water. Over the years, the ground dries up and turns to sand. When spring comes and the ice melts（融化）, the ground becomes looser（更松散的）. Strong winds take the loose sand into the sky.
    Sandstorms are bad for people's health. If people breathe（呼吸） too much sand, they could cough or have asthma（哮喘）.
Sandstorms also give farmers lots of problems. Sometimes their sheep get lost in the storms and never get back home. The winds also tear down farmers' houses.
    What can you do to stop sandstorms? Here’s an idea: Ask you parents to help you plant some trees this spring.
    If you see people cutting down too many trees, tell them about the dangers of sandstorms, and ask your government to stop them from cutting.

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