格里菲思在小鼠身上进行了著名的肺炎双球菌转化实验,关于此实验的结论 不 正确的是 ( )
A .说明了 R 型活细菌是无毒性的
B .说明了 R 型活细菌在一定条件下能够转化为 S 型活细菌
C .说明了肺炎双球菌的遗传物质是 DNA
D .说明了加热杀死的 S 型细菌是无毒性的
下列是某同学在学习世界近代史时制作的时间轴。它反映的学习课题是
A . 走向近代世界 B . 资本主义制度的初步确立
C . 欧洲经济发展 D . 资本主义制度的不断扩展
汉代的人们一般认为,死刑只能在死亡和衰落的季节执行,也就是在秋冬两季执行而不能在春季,否则就妨碍了繁殖和生长,从而引起灾害。它体现的理念主要是
A . 以德治民 B . 尊崇儒术 C . 天人感应 D . 人性本善
小明用气球做了以下三个实验。如图 -1 ,吹风机在工作时,吹风口能 “吸”住气球,是利用了气球上放空气流速大,压强 ______ 。如图 -2 ,气球放在热水烫过的玻璃瓶口,过一会在 ______ 的作用下被 “吸”入瓶中。如图 -3 ,在头发上摩擦过的气球靠近细水流,水流偏离竖直方向,是因为该气球带了 ______ ,对细水流产生了吸引力。
5月12日是汶川地震11周年,时光虽逝,伤痕难愈,大地震带给我们诸多思考。经国务院批准,自2009年起,每年5月12日为全国:( )
A.防灾减灾日
B.地震预警日
C.国家哀悼日
D.感恩日
如图,甲、乙两人(看成点)分别在数轴-3和5的位置上,沿数轴做移动游戏.每次移动游戏规则:裁判先捂住一枚硬币,再让两人猜向上一面是正是反,而后根据所猜结果进行移动.
①若都对或都错,则甲向东移动1个单位,同时乙向西移动1个单位;
②若甲对乙错,则甲向东移动4个单位,同时乙向东移动2个单位;
③若甲错乙对,则甲向西移动2个单位,同时乙向西移动4个单位.
(1)经过第一次移动游戏,求甲的位置停留在正半轴上的概率;
(2)从图的位置开始,若完成了10次移动游戏,发现甲、乙每次所猜结果均为一对一错.设乙猜对次,且他最终停留的位置对应的数为
,试用含
的代数式表示
,并求该位置距离原点
最近时
的值;
(3)从图的位置开始,若进行了次移动游戏后,甲与乙的位置相距2个单位,直接写出
的值.
如图,在矩形 中,
,点 E , F 分别在边
上,且
,按以下步骤操作:第一步,沿直线
翻折,点 A 的对应点
恰好落在对角线
上,点 B 的对应点为
,则线段
的长为 _______ ;第二步,分别在
上取点 M , N ,沿直线
继续翻折,使点 F 与点 E 重合,则线段
的长为 _______ .
下列句子没有语病的一项是( )
A.根据本报和部分出版机构联合开展的调查显示,儿童的阅读启蒙集中在1-2岁之间,并且阅读时长是随着年龄的增长而增加的。
B.为了培养学生关心他人的美德,我们学校决定组织开展义工服务活动,三个月内要求每名学生完成20个小时的义工服务。
C.在互联网时代,各领域发展都需要速度更快、成本更低的信息网络,网络提速降费能够推动“互联网+”快速发展和企业广泛收益。
D.面对经济全球化带来的机遇和挑战,正确的选择是,充分利用一切机遇,合作应对一切挑战,引导好经济全球化走向。
请阅读下面短文,理解其大意,然后从每小题所给的A、B、C三个选项中,选出一个能填入空白处的最佳选项,并在答题卡上将该项涂黑。
When I was about twelve, I ate out with my family. It was a cold winter, and on that night, the wind was really blowing hard.
As my mom and I headed to the 36 from our car, a girl about my age and her mother came up to us. They asked if we had any spare change. My mom right away asked where they lived. They 37 to an old car in a parking lot across the street. The girl said there were six of them living in that car.
My mom said she had something to do after handing the people a few dollars. She sent me inside the restaurant with my dad and my younger sister. But she didn' t come. Later, I 38 she had gone home and put all the food in our cupboards into a few bags. Then, she brought that food over to the car and handed the bags to the family. I wasn' t there when that happened, but I can only imagine the 39 it brought to those people.
A few days later, when I knew what she had done, I asked her 40 she helped those people. She told me that they were unlucky. I remember the face of that girl who had asked us for change. She was the same age as me, yet we looked so 41 .
Here I stood, dressed in 42 new clothes, headed to eat in a restaurant and then backed home to the bedroom for my sister and me. I remember thinking that the other girl didn' t have any food to eat and that she was heading back to a cold car shared 43 five other people.
After painting this picture in my mind, I understood why my mom had helped them. I will never forget what she did that night, and how she taught me one of the best lessons I ever learned.
36. A. park B. bank C. restaurant
37. A. moved B. pointed C. traveled
38. A. focused on B. found out C. thought about
39. A.joy B. pain C. pity
40. A. how B. why C. what
41. A. different B. similar C. clever
42. A. hardly B. almost C. seldom
43. A. in B. for C. with
请阅读下面短文,根据短文内容,在下面的表格中填人与文章意思最符合的单词,并将答案写在答题卡相应的位置上。每空一词。
It is commonly seen that students take pictures of teachers' blackboard-writing using their smart phones. This starts a discussion on whether taking a picture can take the place of taking notes.
Among those in the photo- taking camp, some can' t read their own handwriting. So it' s best to take a picture of teachers' writing so that they can understand the notes. Some take pictures of notes because they know the phone is a safe place to store materials. They may lose paper, but they may not lose their phones. Some take photos because they want to record exact words that have been written on the blackboard.
It may be convenient to use phones as note takers, but is a picture a replacement(替代品)
for the process of note-taking? Can the two be equally effective?
Taking .notes may be an old-fashioned method, but a method which has a long history doesn't mean it's out of date. Taking notes is a traditional way to help make preparations for getting and understanding information. Teachers encourage students to take notes because the act of doing so is more than only recording necessary information一it requires students to ask questions about what they don' t know. The act of writing information down forces the brain to begin to memorize,establishing the building blocks of learning something new.
I' m not sure which is better. For now, I allow students to take notes however they see fit一handwritten or photographed一because I think that some notes, no matter the method of
note-taking, are better than none.
Taking pictures | Taking notes |
Help students who are not 59 at handwriting to understand the notes. Be much safer to store materials. Record words that have been written on the Blackboard 60 . | Help 61 for getting and understanding information. Record necessary information and ask 62 about unknown things. Help the students to put information into memory by processing and combining it. |
Handwritten notes and photographed notes are 63 allowed because some notes are better than none. |
下列景观与气候的描述搭配正确的是( )
A、多雨季节一派枯黄——热带雨林气候
B、终年高草茂盛——热带草原
C、树木叶片有蜡质——地中海气候
D、雨热同期——温带海洋气候
2018年4月16日,美国商务部宣布立即重启对中兴通讯的制裁禁令,禁止美国企业与中兴通讯进行任何形式的业务往来。接着,美国政府又以种种形式,采取多种手段打压制裁中国高科技企业华为公司。上述事件让我们更加感受到( )
①今天的中国,在国际舞台上扮演着越来越重要的角色
②现实世界,国与国之间存在着激烈的竞争
③新世纪,我国的发展面临严峻的外部形势
④坚持对外开放基本国策,大力实施科教兴国、人才强国战略,是我们的必然选择
A. ①②③ B. ②③④ C. ①③④ D. ①②③④
节约用水和合理开发利用水资源是每个公民应尽的责任和义务。下列关于水的认识正确的是 ( )A.过滤能除去天然水中所有的杂质
B.将活性炭放入硬水中可使其软化
C.工业废水要经过处理后再排放
D.过量使用农药、化肥不会造成水体污染