(2019·全国卷Ⅱ)Bacteria are an annoying problem for astronauts. The microorganisms (微生物) from our bodies grow uncontrollably on surfaces of the International Space Station, so astronauts spend hours cleaning them up each week. How is NASA overcoming this very tiny big problem? It's turning to a bunch of high school kids. But not just any kids. It is depending on NASA HUNCH high school classrooms, like the one science teachers Gene Gordon and Donna Himmelberg lead at Fairport High School in Fairport, New York.
HUNCH is designed to connect high school classrooms with NASA engineers. For the past two years, Gordon's students have been studying ways to kill bacteria in zero gravity, and they think they're close to a solution (解决方案). “We don't give the students any breaks. They have to do it just like NASA engineers,” says Florence Gold, a project manager.
“There are no tests,” Gordon says. “There is no graded homework. There almost are no grades, other than‘Are you working towards your goal?’ Basically, it's ‘I've got to produce this product and then, at the end of the year, present it to NASA.’Engineers come and really do an inperson review, and ... it's not a very nice thing at times. It's a hard business review of your product.”
Gordon says the HUNCH program has an impact (影响) on college admissions and practical life skills. “These kids are so absorbed in their studies that I just sit back. I don't teach.” And that annoying bacteria? Gordon says his students are emailing daily with NASA engineers about the problem, readying a workable solution to test in space.
篇章导读:本文是一篇说明文,介绍了美国一所中学与NASA合作的联合科研项目,解决国际空间站中的细菌问题。
13.What do we know about the bacteria in the International Space Station?
A.They are hard to get rid of.
B.They lead to air pollution.
C.They appear in different forms.
D.They damage the instruments.
14.What is the purpose of the HUNCH program?
A.To strengthen teacherstudent relationships.
B.To sharpen students' communication skills.
C.To allow students to experience zero gravity.
D.To link space technology with school education.
15.What do the NASA engineers do for the students in the program?
A.Check their product. B.Guide project designs.
C.Adjust work schedules. D.Grade their homework.
16.What is the best title for the text?
A.NASA: The Home of Astronauts
B.Space: The Final Homework Frontier
C.Nature: An Outdoor Classroom
D.HUNCH: A College Admission Reform
K—O 2 电池结构如图, a 和 b 为两个电极,其中之一为单质钾片。关于该电池,下列说法错误的是
A . 隔膜允许 K + 通过,不允许 O 2 通过
B . 放电时,电流由 b 电极沿导线流向 a 电极;充电时, b 电极为阳极
C . 产生 1Ah 电量时,生成 KO 2 的质量与消耗 O 2 的质量比值约为 2.22
D . 用此电池为铅酸蓄电池充电,消耗 3.9g 钾时,铅酸蓄电池消耗 0.9g 水
我国新冠疫情防控已取得了举世瞩目的成绩,但全球疫情形势仍然严峻。为更有效地保护人民身体健康,我国政府正在大力实施全民免费接种新冠疫苗计划,充分体现了党和国家对人民的关爱。目前接种的新冠疫苗主要是灭活疫苗,下列叙述正确的是( )
① 通过理化方法灭活病原体制成的疫苗安全可靠
② 接种后抗原会迅速在机体的内环境中大量增殖
③ 接种后可以促进 T 细胞增殖分化产生体液免疫
④ 二次接种可提高机体对相应病原的免疫防卫功能
A . ①④ B . ①③ C . ②④ D . ②③
某小组研究热敏电阻阻值随温度的变化规律,根据实验需要已选用了规格和量程合适的器材。
( 1)先用多用电表预判热敏电阻值温度的变化趋势,选择适当倍率的欧姆档,将两表笔_____,调节欧姆调零旋钮,使指针指向右边“0Ω”处。测量时观察到热敏电阻温度越高,相同倍率下多用电表指针向右偏转角度越大,由此可判断热电阻阻值随温度的升高而_____。
( 2)再按图 9 连接好电路进行测量。
①闭合开关 S 前,将滑动变阻器 R 1 的滑片滑到 ______端(选填“a”或“b”)。
将温控室的温度设置为 T,电阻箱 R 0 调为某一阻值 R 01 ,闭合开关 S,调节滑动变阻器R 1 ,使电压表和电流表的指针偏转到某一位置。记录此时电压表和电流表的示数、 T 和 R 01 ,断开开关 S。
再将电压表与热敏电阻 C 端间的导线改接到 D 端,闭合开关 S。反复调节 R 0 和 R 1 ,使电压表和电流表的示数与上述记录的示数相同。记录此时电阻箱的阻值 R 02 ,断开开关 S。
②实验中记录的阻值 R 01 _____R 02 (选填 “大于”、“小于”或“等于”)。此时热敏电阻阻值R T =_____。
( 3)改变温控室的温度,测量不同温度时的热敏电阻阻值,可以得到热敏电阻阻值随温度的变化规律。
选项 | 实验 | 现象 | 结论 |
A | 25℃,两片相同的A1片分别和等体积稀HNO3和浓HNO3反应 | 前者产生无色气体,后者产生红棕色气体,且后者反应更加剧烈 | 其他条件相同时,反应物浓度越大, 反应速率越快 |
B | 向某液溶胶中分别加入石膏和硫酸钠的溶液 | 前者明显聚沉,后者几乎无变化 | 该胶体微粒带负电荷 |
C | SO2通入BaCl2溶液,然后滴入稀硝酸 | 有白色沉淀产生,加入稀硝酸后沉淀不溶解 | 所得沉淀为 BaSO3,后转化为 BaSO4 |
D | 将炭和浓H2SO4的混合物加热,产生的气体通入石灰水 | 石灰水变浑浊 | 碳被氧化成CO2 |
A. A B. B C. C D. D
北宋中期以后乡村出现了受雇于高豪之家的代役人,顶替雇主到地方官府当差。募役法实行后,这一类代役人大部分被国家认可,南宋时渐成常态。代役人现象的普及
A . 反映了商品经济发展 B . 加剧了乡村阶层对立
C . 削弱了基层治理能力 D . 加速了农村人口流动
福建福州高三期中)质量为m的汽车行驶在平直的公路上,在运动过程中所受阻力不变。当汽车的加速度为a,速度为v时发动机的功率为P1,则当功率恒为P2时,汽车行驶的最大速度为( )
A. B.
C. D.