题干

设F1,F2.分别是双曲线
x
2
a
2
-
y
2
b
2
=1a>0,b>0
的左,右焦点,若在双曲线右支上存在点P,满足|PF2|=|F1F2|,且F2到直线PF1的距离等于双曲线的实轴长,则该双曲线的渐近线方程为(   )

A:3x±4y=0

B:3x±5y=0

C:5x±4y=0

D:4x±3y=0

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答案(点此获取答案解析)

D

同类题4

阅读下文,回答相关问题。
                                                                                                                                       遥远的炊烟
                                                                                                                                           鲁先圣
        ①只要在乡村生活过,有谁不怀念村庄上空那袅袅升起的炊烟? 袅袅的炊烟在房屋的脊梁上盘旋,在树梢的鸟巢旁飘荡,在胡同的拐角里踱步,最后都凝聚成片片朦胧的烟霞。在那袅袅的炊烟里,有母亲的目光,也有父亲洪钟般的声音。
       ②有多久没有看到过炊烟了?城市里没有炊烟,城市里用的是煤气液化气,即使有了些许的炊烟,也是有害的气体,是不会让人留恋的。况且,城市里的人们,也没有时间留意炊烟,大家都匆匆忙忙,谁会有时间在意稍纵即逝的炊烟?炊烟只属于宁静的乡村,只属于浑厚的黄土地。
        ③只有当停下匆匆步履的时候,只有当心灵归于一份淡雅和安静的时候,那袅袅的炊烟会从久远的记忆中升起来,瞬间就弥漫了你整个的心灵,它像一幅美丽的水墨画,让人有不尽的遐想。
        ④童年的时候,炊烟是娘做好的可口的饭菜。伙伴们成群结队去村外的田野里玩耍,去村头的小河里嬉戏。兴致起来,忘记了时间,忘记了回家。这个时候不知道谁说一声,我家房顶上没有烟了,娘做好饭了。大家立刻都齐刷刷地把目光投向村里,纷纷寻找自己家的房顶。不久前还袅袅升起着的炊烟,都已经渐渐散尽了,娘把饭都做好了。大家自然都收了心,赶快追逐着跑向村里,跑回自己的家里,那里有娘可口的饭菜等着啊。再不回家,娘就要到村口呼唤儿子了。
        ⑤炊烟是汉子们心底的温暖。太阳升起来了,汉子们赶着牲口,拉着牛车,说说笑笑地到村外的田地里劳作。到了中午了,汉子们累了的时候,村里的炊烟也升起来了。这个时候,大家纷纷卸下牲口,在地头坐下,点燃上一支烟,大家的目光都会朝向通往村里的小路。那条小路上,渐渐地,成群结队的妇女,提着饭菜从村里的炊烟里走来了。汉子们的疲劳消失了,那不尽的温暖扑面而来了。
        ⑥炊烟是                   。不论到了天南海北还是在都市庙堂,不论你名满天下还是腰缠万贯,最让你动心的,一定是故乡茅屋上升起的那袅袅炊烟啊!不论你遭受了多么深重的创伤,那随风飘浮的缕缕炊烟,顷刻之间就把你隐藏在了无边的温暖里。
         ⑦当我们忆起年迈的母亲,母亲的身影多半是在炊烟里。有多少回啊?当我们远行回到家里,当我们喊娘的时候,母亲的身影正在炊烟里忙碌。
         ⑧没有风的时候,炊烟就像一棵树,从家里的灶房里生长起来,然后与全村的树聚合成一棵参天大树。有风的时候就不同了,家家的炊烟刚刚冒上房顶,就迅速汇集,变成一片片灰色的云,飘浮到村庄的上空,最后都消失到无边的旷野里。其实,不论是有风的时候还是无风的时候,乡村上空的炊烟都是一幅动人的画卷。可是炊烟与画卷又不同,因为炊烟里还有麦子的香味,更有母亲殷殷的目光。

同类题5

先通读下面的短文,然后根据短文内容,在文章后表格的空格内填入一个最恰当的单词。所填单词必须写在答题卡对应题号的横线上。每个空格只能填一个单词。

    Clothing(服装) is a language. We can look at the traditional clothing to know more about culure.

    Africa has a long history and a rich culture, and this is shown in traditional dress. The three colours—red, gold and green, are often used in the clothing. The first colour represents the blood of millions of people who fought for freedom; the second, rich resources of the African earth; and the third, the grassland of home.

    Because clothing has strong social meanings, people are very careful in choosing what to wear. It would be a serious mistake to wear the wrong clothes, or to dress in the wrong way. For example, in Ghana, a woman should wear her waistband (腰带) differently according to the importance of the social event.

    Traditional dress also tells us about everyday life. African designs are famous for loose (宽松的) clothing. The temperature there can be very high during the daytime but very low at night, so it requires that the clothes are comfortable for daily life.

    Today although more and more young people like wearing Western clothes, especially in big cities in Africa, traditional African dress is still quite valuable. This is because it has deep cultural meanings.

Traditional Dress in Africa

Different colours

 The three most ____ colours used in clothing are red, gold and green.

 Different colours ____ for different things: the blood of freedom fighters, resources of the earth and the grassland of home.

Social meanings

 Because clothing has strong social meanings, people have to choose what to wear ____

 Women in Ghana even wear different waistbands according to how important the event is.

Everyday life

 Because the temperature ____ greatly, clothes are usually loose and comfortable.

 Though Western clothes are popular with young people in some areas, traditional clothes are still of great ____