已知直线y=-2x+m,圆x2+y2+2y=0. (1)m为何值时,直线与圆相交

题型:解答题

问题:

已知直线y=-2x+m,圆x2+y2+2y=0.

(1)m为何值时,直线与圆相交?

(2)m为何值时,直线与圆相切?

(3)m为何值时,直线与圆相离?

考点:直线与圆的位置关系
题型:解答题

任务型阅读。

    There are many things you can do to improve your memory. Among them are different memorizing methods

as well as taking special care of your health.

    It is important that you regularly stimulate (刺激) your brain to make your memory more efficient. You can

do this by doing activities that you don't normally do and by changing your daily habits. Learning a new skill

helps your brain to develop. When trying to memorize something, you should not allow other thoughts to entre

your mind because this will reduce your chances of making right memories.

    An excellent way to help memory is to connect information with pictures. It is called memonics (记忆术).

Try to see the pictures in your mind. Taking notes, being organized and keeping a diary will also be useful ways. 

    Healthy food and plenty of vitamins are good for your memory to work properly. Drinking a lot of water also

helps to keep your memory. You must allow your brain to have enough sleep and a good rest. When you are

asleep, your brain stores memory. Not enough sleep can cause problems with the storing information and being

tired will stop you from being able to concentrate(集中) well. Caffeine in tea and coffee is very good at

preventing sleepiness and helping concentrate well, but they can also cause problems with memory.

    In order to concentrate well, you must be relaxed. Generally keeping fit and regular health checks are both

important as well-not just for improving your memory.

根据上面短文内容填空。

1. Different memorizing methods and _____________ can improve your memory.

2. To make your memory more efficient, you ______________.

3. You should not allow other thoughts to entre your mind because you will ____________ to memorize things

   correctly.

4. ____________, plenty vitamins, drinking a lot of water, ___________ and a good rest are good for your

   memory to work properly, too

5. The good thing about caffeine in tea and coffee is that caffeine can _____________.

题型:解答题

若有以下定义和语句: double r=99,*p=&r; *p=r; 则以下正确的叙述是( )

A.以上两处的*p含义相同,都说明给指针变量p赋值

B.在"double r=99,*p=&r;"中,把r的地址赋值给了p所指的存储单元

C.语句"*p=r;"把变量r的值赋给指针变量p

D.语句"*p=r;"取变量r的值放回r中

题型:解答题

风热头痛的特点是

A.急性期应适当活动
B.注意对中风先兆症状的观察及治疗
C.注意功能锻炼
D.节制饮食
E.防止变证发生

题型:解答题

驾驶机动车超车要注意什么

A.从前车的右侧超越

B.从前车的左侧超越

C.从左右两侧均可超越

D.不受速度限制

题型:解答题

出租车驾驶员私自改装、调整计价器造成计费失准的,扣除出租车驾驶员服务质量信誉考核分值计分20分。

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