记关于x的不等式x-ax+1<0的解集为P,不等式|x-1|≤3的解集为Q.(1

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问题:

记关于x的不等式
x-a
x+1
<0
的解集为P,不等式|x-1|≤3的解集为Q.
(1)若a=3,求P.
(2)若P⊆Q,求实数a的取值范围.
考点:集合间的基本关系绝对值不等式
题型:解答题

阅读理解。

     It's not easy being a teenager (13至19岁青少年)-nor is it easy being the parent of a teenager. You can

make your child feel angry, hurt, or misunderstood by what you say without realizing it yourself. It is important

to give your child the space he needs to grow while gently letting him know that you you'll still be there for

him when he needs you.

     Expect a lot from your child, just not everything. Except for health and safety problems,such as drug use

or careless driving; consider everything else open to discussion. If your child is unwilling to discuss something,

don't insist he tell you what's on his mind. The more you insist, the more likely that he'll clam up. Instead, let

him attempt to solve (解决) things by himself. At the same time, remind him that you're always there for him

when he seek advice or help. Show respect for your teenager's priyacy (隐私). Never read his mail or listen in

on personal conversations.

     Teach your teenager that the family phone is for the whole family. If your child talks on the family's

telephone for too long, tell him he can talk for 15 minutes, but then he must stay off the phone for at least an

equal period of time. This not only frees up the line so that other family members can make and receive calls,

but teaches your teenager moderation (节制). Or if you are open to the idea, allow your teenager his own phone

that he pays for with his own pocket money or a part-time job.

1. The main purpose of the text is to tell parents _____. [ ]

A. how to get along with a teenager

B. how to respect a teenager

C. how to understand a teenager

D. how to help a teenager grow up

2. What does the phrase "clam up" in Paragraph 2 probably mean? [ ]

A. Become excited.

B. Show respect.

C. Refuse to talk.

D. Seek help.

3. What should parents do in raising a teenager according to the text? [ ]

A. Not allow him to learn driving or take drugs.

B. Give him advice only when necessary.

C. Let him have his own telephone.

D. Not talk about personal things with him.

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下列哪一项不是常见的继发性高血压()

A、肾动脉狭窄

B、原发性醛固酮增多症

C、主动脉瘤

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不是透平真空系统的设备是()。

A、冷凝器

B、凝结水泵

C、汽轮机

D、喷射泵

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表面改性的目的是什么?它主要针对何种粉体材料?

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若水泵出口压力突然下降你判断可能的原因?

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