某兴趣小组利用如图所示电路进行如下的实验研究。 (1)闭合S1,断开S2,调

题型:计算题

问题:

某兴趣小组利用如图所示电路进行如下的实验研究。

       

(1)闭合S1,断开S2,调节电源电压,得到上表中三组数据。请根据表中的数据,计算电阻R的阻值。(计算结果保留1位小数)

(2)断开S1,闭合S2,调节电源电压进行有关测量。根据记录到灯泡L的电压和电流的数据绘制成电压和电流的关系图像(如下图所示)。由图像可知,当电压表示数为2V时,50s时间内,灯泡L消耗了多少电能?

(3)同时闭合S1和S2,调节电源电压,当灯泡L的功率为1W时,电阻R与灯泡L的总功率是多大?

考点:电功率的计算欧姆定律及其应用电功或电能的计算
题型:计算题

随着《我的兄弟叫顺溜》的热播,作为《我的兄弟叫顺溜》拍摄地的安徽省寿县借着古城墙气势雄伟、有完整的防御体系,历史上有“铁打寿州城”之说打起了旅游牌。这体现寿县人民

①正确有效地发挥了主观能动性 ②把资源优势转化为经济优势 ③履行经济职能,发展文化产业 ④做到一切从实际出发

A.①②③④

B.①②④

C.②③

D.④

题型:计算题

2010年1月,温 * * * * 在国家科学技术奖励大会上讲话中指出,科技创新是

1 经济持久繁荣的不竭动力

2 应对国际金融危机的强大武器

3 党和国家当前的中心工作

4 社会主义的根本任务

A.1 2

B.2 3

C.1 3

D.3 4

题型:计算题

Almost every day the media discovers an African American community fighting some form of environmental threat from land fills, garbage dumps, petrochemical plants, refineries, bus depots, and the list goes on. For years, residents watched helplessly as their communities became dumping grounds.
But citizens didn’t remain silent for long. Local activists have been organizing under the mantie of environmental justice since as far back as 1968. More than three decades ago, the concept of environmental justice had not registered on the radar screens of many environmental or civil rights groups. But environmental justice fits squarely under the civil rights umbrella. It should not be forgotten that Dr. Martin Luther King Jr. went to Memphis on an environmental and economic justice mission in 1968, seeking support for striking garbage workers who were underpaid and whose basic duties exposed them to environmentally hazardous conditions.
In 1979, a landmark environmental discrimination lawsuit filed in Houston, followed by similar litigation efforts in the 1980s, rallied activists to stand up to corporations and demand government intervention.
In 1991, a new breed of environmental activists gathered in Washington, D.C. , to bring national attention to pollution problems threatening low-income and minority communities. Leaders introduced the concept of environmental justice, protesting that Black, poor and working-class communities often received less environmental protection than White or more affluent communities. The first National People of Color Environmental Leadership Summit effectively broadened what "the environment" was understood to mean. It expanded the definition to include where we live, work, play, worship and go to school, as well as the physical and natural world. In the process, the environmental justice movement changed the way environmentalism is practiced in the United States and, ultimately, worldwide.
Because many issues identified at the inaugural summit remain unaddressed, the second National People of Color Environmental Leadership Summit was convened in Washington, D.C. , this past October. The second summit was planned for 500 delegates ; but more than 1,400 people attended the four-day gathering.
"We are pleased that the Summit Ⅱ was able to attract a record number of grassroots activists, academicians, students, researchers, planners, policy analysts and government officials. We proved to the world that our movement is alive and well, and growing," says Beverly Wright, chair of the summit. The meeting produced two dozen policy papers that show powerful environmental and health disparities between people of color and Whites.

In Paragraph 1, the word "residents" refers to ______ in particular.

A.ethnic groups in the U.S.

B.the American general public

C.African Americans

D.the U.S. working-class

题型:计算题

波形膨胀节有何作用?本装置哪些地方使用波形膨胀节?

题型:计算题

大蒜中含硫成分多达30余种,其中二烯丙基-硫化物生物活性最强。( )

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