充填孔与油套串通，油管压力降为（）MPa，此时就完成了封隔器坐封，并打开了填砂通道。

[1] Stress for a teenager is as real a problem as stress for an adult. Therefore, it’s important to understand the causes of stress in teenagers.

[2] When parents change their jobs or if the family decides to move to a different place, the child has to change schools, find new friends, adapt to the new social circle and fit into new groups. It is always difficult for children to adapt to such changes, which can be a serious cause of stress in their life.

[3] Academic difficulties, such as inability to understand a certain subject can cause stress. Not every child has the ability to understand every subject. Some kids need extra help besides school work to grasp a few concepts. Poor academic performance is often laughed at and is looked down upon by both teachers and peers. In such cases, it can make the child feel isolated, neglected and hurt. All of this, put together, can add to stress, which many times worsen grades.

[4] Extra curricular activities (课外活动) such as playing a sport, or attending art classes can weigh heavily on your child’s mind. Balancing school and extra curricular activities does seem like a burden when you have to be outstanding at both. When the pressures from both the ends get unmanageable, teenagers tend to get tired and annoyed. Tiredness sets in, leading to stress related issues such as lack of concentration in school.

[5] These are the common causes of stress in teenagers, which can be noticed through signs such as poor memory, anxiety, negative and pessimistic attitude. If the signs of teenage stress go unrecognized for a long time, it can make the child emotionally out of balance. And next step, if this happens, it is necessary for parents to know _________________.

小题1:What’s the main idea of the passage?

___________________________________________________________________________

小题2:Why poor academic performance causes stress for children? ( no more than 20 words)

___________________________________________________________________________

小题3: How can parents notice that their teenagers are under stress? (no more than 15 words)

___________________________________________________________________________

小题4: What common causes of stress in teenagers were introduced by the author? (no more than 3 words for each)

①____________________   ②____________________    ③_____________________

小题5: Fill in the blank in Paragraph 5 with proper words.（no more than 8 words）

—How is your journey?  

—________.    [ ]

A. Fine,thank you            

B. I like it    

C. It's great                        

D. I had a good time

酚二磺酸分光光度法测定水中硝酸盐氮时，为使硝酸盐标准贮备液有一定的稳定时间，需在溶液中加入2ml氯仿（三氯甲烷）作保存剂，至少可称定6个月。

转速、电流双闭环直流调速系统中的电流调节器、转速调节器，各有何作用？

下列各项中，可以成为投保人的是( )。

A．对保险标的不具有保险利益的人

B．限制民事行为能力人

C．无民事行为能力人

D．10岁女孩的监护人