Tom doesn't like play the piano.
中
是函数
的极值点,则
=( )
B .
C .
或
D .
或无意义
﹣10
B . 10﹣10
C . 30﹣10
D . 20﹣10
—Yes. But they(be not) free yesterday evening. They helped me with my lessons.


Everyone meets difficulties in their life. Daniel Kish was born with a special eye illness and lost his eyesight(视力) before he was only 14 months old.
Soon after, however, he started to do an amazing thing. He learned to make clicks(咔哒声) with his tongue(舌头) to help him move around. Kish now moves around using sonar(声呐). He is so good at it that he can ride a bicycle by himself on public roads. And he started the organization(组织) World Access(通道) for the Blind(WAFTB) in 2000, teaching others how to use sonar. In the interview with National Geographic, he explains how the sonar works.
"When I make a click sound, it produces sound waves(声波). These waves reflect(反射) off surfaces(表面) all around and return to my ears. My brain then deals with(处理) the sound and turns it into pictures in my mind. Each click is like a camera flash, which helps me make a 3-D picture of the things around me. It's like having a conversation with the environment."
Kish feels it is exciting to ride a bike using a sonar. "It may sound a bit dangerous to move around the world in this way," he says. "But most people in the world live in fear(害怕) of things that they imagine. I love hiking and mountain-biking. I go almost everywhere. And I've never had an accident and hurt myself."
He is happy to be able to help more blind(瞎的) children to improve their life. "We've helped over 10,000 students in nearly 40 countries," he tells the reporter.
①The sound waves reflect off surfaces.
②The person makes a clicking sound.
③The brain turns the sound into pictures.
④The sound waves reach the person's ears.
的图象与
轴、
轴交于
、
两点,与反比例函数
的图象相交于
、
两点,分别过
、
两点作
轴,
轴的垂线,垂足为
、
,连接
、
,有下列结论:①
与
的面积相等;②
;③
;④
其中正确的个数有( )
①鲁迅《记念刘和珍君》一文,笔锋犀利,力透纸背。鲁迅用文字去揭露统治者的丑恶面目,鞭挞统治者的罪恶行径。
②西樵山上的南海观音寺,规模浩大,香火鼎盛,慕名前来参拜的僧侣信徒很多,每逢法会更是香客如云,不绝如缕。
③周末不妨与大自然展开一次心灵对话,到佛山美轮美奂的绿岛湖畔欣赏碧波荡漾,感受佛山城市升级带来的新变化。
④韩国以允许美国在其领土部署雷达监控范围可覆盖东北亚的萨德系统来防范朝鲜的核威慑,这无异于火中取栗。
⑤中国西昌卫星发射中心以“一箭双星”成功发射北斗三号组网卫星,北斗卫星导航系统实现全球覆盖可计日程功。
⑥台风“天鸽”带来的强降雨,导致广东部分地区城市内涝。灾情严重,扣人心弦 , 相关部门正紧急行动组织救灾。
材料一 (英国)1832~1868年间,共更换了10届内阁,其中2届发生在大选之后,8届因平时下院投票选成。——《英国政治制度史》
材料二 在选任政府方面,不管我们的宪法在理论上授予女王多么大的自由,在实践中这种自由是不存在的。
材料三 拥有下院多数事事可行,没有下院多数一事无成。
请回答:
一株桃树,长在一棵胡桃树旁边,它满怀嫉恨地望着枝丫结满了累累果实的胡桃树。
“为什么那棵树就长这么多果实,而我长这么少呢?”它想到,“这是不公平的,我一定要想办法也长得那么多。”
“千万别这样想呀!”一株李树看透了桃树的心思,劝告道,“你难道没有看到胡桃树的树干长的有多粗大吗?你没有看到它的枝丫多强壮吗?我们每个人都要量力而为,想法子长出好果子!要重质不要重量。”
可是桃树已经嫉恨得糊涂了,压根儿不愿听。它要求它的树枝从大地吸收更多的养料,要它的细枝输送更多的树汁。于是它展开了更多的花朵,花朵都结了果实。由头到脚全结满了桃子。
可是当桃子成熟时,它们的重量就增加了,以至于枝丫都负担不起它们,而且树干也撑不住那些果实的重量。桃树呻吟一声,弯了,接着“咔嚓”一声巨响,树干断了,整株树倒了下来。桃子全烂在了胡桃树的脚下。
这则寓言告诉了我们什么道理?
My brother and I like sports very much. We like (run), playing basketball, swimming and so on. Of all the (sport), we like swimming (good). Swimming is really . (interest). (连词) you swim in the pool, you look like a (love) fish. Very cool. You will be happy if you can (swim). If you often swim, you will be (health). (swim) can bring you a lot of fun. Come and swimming (介词) us in the following two clubs.
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完成下题。
“超级地球”位于( )
