下列非洲的矿产中储量和产量都居世界首位的是( )
A、煤、铁 B、石油、铀 C、铁、锰 D、金刚石、黄金
5.史载:明代江南昆山县的农家,“麻缕机织之事,则男子素习焉,妇人或不如也”,但乡村妇女“凡耕耘、刈获、桔槔之事,与男子共其劳”。材料反映了( )
A.男尊女卑的社会秩序得到巩固 B.男子是家庭手工业的主要劳动力
C.小农经济没有绝对的性别分工 D.资本主义萌芽的出现和缓慢发展
Although there are still ______ natural resources in some areas, we should protect them from now on.
A. apparent B. abstract C. abundant D. abnormal
我国扶贫经历了从最初单纯性“输血”式扶贫到开发性“造血”式扶贫的过程,即从政府向贫困人口提供满足最低生活需要的物质援助到把国家政策扶贫、投资扶持等与贫困地区干部群众自力更生结合起来的过程。这启示我们:( )
A.要重视意识的作用,重视精神的力量 B.要坚持内因与外因相结合
C. 要解放思想、求真务实、与时俱进 D.要不失时机促成事物的飞跃和发展
两个质量相同的小球用不可伸长的细线连结,置于场强为E的匀强电场中,小球1和小球2均带正电,电量分别为q1和q2(q1>q2)。将细线拉直并使之与电场方向平行,如图所示。若将两小球同时从静止状态释放,则释放后细线中的张力T
为(不计重力及两小球间的库仑力) ( )
A.
B.
C.
D.![]()
![]() |
计算6÷(-3)的结果是【 】
A.-
B.-2 C.-3 D.-1
8
把盛有酵母菌和葡萄糖混合液的装置(如图)置于适宜温度下,一段时间后,经检测,装置中葡萄糖减少了a摩尔,气体的体积总量增加了b摩尔。以下关于酵母菌细胞呼吸的分析不正确的是( )

A.无氧呼吸消耗的葡萄糖为0.5b摩尔
B.有氧呼吸产生的CO2量为6a-b摩尔
C.细胞呼吸产生的CO2量为6a-2b摩尔
D.细胞呼吸消耗的O2量为6a-3b摩尔
与直线x﹣y﹣4=0和圆x2+y2+2x﹣2y=0都相切的半径最小的圆的方程是( )
A.(x+1)2+(y+1)2=2 B.(x+1)2+(y+1)2=4 C.(x﹣1)2+(y+1)2=2 D.(x﹣1)2+(y+1)=4
One day when I was 12, my mother gave me an order: I was to walk to the public library, and borrow at least one book for the summer. This was one more weapon for her to defeat my strange problem— inability to read.
In the library, I found my way into the “Children’s Room.” I sat down on the floor and pulled a few books off the shelf at random. The cover of a book caught my eye. It presented a picture of a beagle. I had recently had a beagle, the first and only animal companion I ever had as a child. He was my secret sharer, but one morning, he was gone, given away to someone who had the space and the money to care for him. I never forgot my beagle. Without opening the book titled Amos, the Beagle with a Plan, I borrowed it from the library for the summer.
Under the shade of a bush, I started to read about Amos. I read very, very slowly with difficulty. Though pages were turned slowly, I got the main idea of the story about a dog who, like mine, had been separated from his family and who finally found his way back home. That dog was my dog, and I was the little boy in the book.
My mother’s call returned me to the real world. I suddenly realized something: I had read a book, and I had loved reading that book. Everyone knew I could not read. But I had read it. Books could be incredibly wonderful and I was going to read them.
I never told my mother about my “miraculous” (奇迹般地) experience that summer, but she saw a slow but remarkable improvement in my classroom performance during the next year. And years later, she was proud that her son had read thousands of books, was awarded a PhD in literature, and authored his own books, articles, poetry and fiction. The power of the words has held.
24.The author’s mother told him to borrow a book in order to_____.
A. encourage him to do more walking B. help cure him of his reading problem
C. let him spend a meaningful summer D. make him learn more about weapons
25.The book caught the author’s eye because_____.
A. it contained pretty pictures of animals B. he found its title easy to understand
C. he was reminded of his own dog D. he liked children’s stories very much
26.What can be concluded from the last paragraph?
A. The author’s mother rewarded him with books.
B. The author’s mother read the same book.
C. The author has become a successful writer.
D. The author has had happy summers ever since.
27.Which one could be the best title of the passage?
A. My Passion for Reading
B. Mum’s Strict Order
C. Reunion with My Beagle
D. The Charm of a Book
某含氧有机化合物可以作为无铅汽油的抗爆震剂,它的相对分子质量在80~100之间,含C的质量分数为68.2%,含H的质量分数为13.6%,核磁共振氢谱显示该分子中有两种吸收峰,面积比为1:3。
(1)写出其分子式(要求有计算过程)。
(2)写出该物质的结构简式及所含的官能团的名称。
“我希望世界各地的文化之风都能尽情地吹到我的家园,但是我不能让它把我连根带走。”甘地这句名言强调的是( )
A.要扬弃传统文化,革故鼎新
B.要承认不同民族文化具有共同性
C.要汲取其他民族文化的长处 ,也要保持本民族文化的特色
D.要尊重世界文化的多样性,促进世界文化繁荣和发展
森林是一巨大的天然“氧吧”,因为绿色植物在光合作用下可以放出大量的氧气.小明同学为测量地球表面植物吸收太阳能的本领,做了如下实验:用一脸盆装6kg的水,水面的表面积为0.1m2,经太阳垂直照射15min,温度升高了5℃.请计算:
(1)实验时6kg的水吸收了多少热量?
(2)若地表植物接收太阳能的能力与水相等,每平方米绿色植物每秒接收的太阳能为多少焦耳?
(3)100 m2绿地每秒可以放出多少升的氧气?(若绿色植物在光合作用下每吸收103J的太阳能可以放出0.05L的氧气)
若cos A=,
则
=( )
A.
B. C. D.0
如图所示,质量为m的木块在质量为M的长木板上,m在水平拉力作用下向右滑行,长木板仍处于静止状态.长木板与地面间动摩擦因数为
,木块与长木板间动摩擦因数为
,则长木板受地面摩擦力大小一定为( )

A.
B.![]()
C.
D.![]()
已知集合
,则
=
A.
B.
C.
D.![]()
如图,在四边形ABCD中,AB=BC=CD=DA,对角线AC与BD相交于点O,若不增加任何字母与辅助线,要使得四边形ABCD是正方形,则还需增加的条件是___________.

a※b是新规定的这样一种运算法则:a※b=a2+2ab,
例如3※(-2)=32+2×3×(-2)=-3
(1)试求(-2)※3的值
(2)若1※x=3.求x的值
(3)若(-2)※x=-2+x,求x的值
水、无机盐、尿素的主要排泄途经是( )
A. 皮肤 B. 肾脏 C. 肺 D. 肛门