D

    Young people can have problems with their minds. Some students become worried because they have to study very hard; others have trouble getting on well with people like their parents or classmates.

    Li Wei, a junior 2 student from Hefei, could not understand his teacher and did badly in his lessons. He became so worried about it that he started to hurt himself with a knife.

    Another 14-year-old student, Yang Fang from Guangzhou, was afraid of exams. She got very nervous, and when she looked at the paper, she couldn't think of anything to write.

    In fact, many students have mental (心理的) problems. However, most of them don't ask for advice or help. Some think they will look stupid if they go to a doctor; others don't want to talk about their secrets.

    Liang Yuezhu, a teacher, has the following advice for young people:

    Talk to your parents or teachers often.

    Take part in group activities and play sports.

    Go to a doctor if you feel unhappy or unwell.

设函数$f\left(x\right)=x^3-{\left(\frac{1}{2}\right)}^{x-2}$，则其零点所在区间为（　　）

完形填空

     People have been raising pigeons(鸽子) for about 10,000 years. And pigeon  keepers use  different kinds of pigeons for different 1Some people use pigeons for 2 For example, in parts of China people cook a special meal with pigeon to celebrate the New Year.

Some people also keep pigeons because they look especially 3There are many interesting kinds of these “pretty” pigeons. Different kinds of pigeons have interesting features 4 long, soft tail feathers or designs on their heads. The owners of these kinds of pigeons enter them in 5  and the best looking pigeons are chosen to win prizes.

     But pigeons have many othe6   too. Pigeons can fly long distances without growing 7 . They also have another8sense. No matter how far from home they are, pigeons can usually fly back to where they9This is often called a “homing sense”. This sense makes them good for carrying10

     In many cities around the world, pigeons live in special houses, and pigeon keepers spend a lot of money and time11 their birds. When someone has a very good pigeon, he is very12    He may also have a way to make money.  But this is not usually the main13 people keep pigeons. For some people, they keep pigeons as a hobby.

     People love pigeons so much that they even take them14 when they move to a new country. They15 these birds as their children.  “When you are looking at a pigeon in the sky you feel free. It is the best feeling you have in a strange country”, a pigeon lover says.