在一定条件下,向2L密闭容器中加入2 mol N2和10 mol H2发生反应N

题型:不定项选择题

问题:

在一定条件下,向2L密闭容器中加入2 mol N2和10 mol H2发生反应N2+3H22NH3,2 min时,测得剩余N2为1 mol,对于此化学反应速率表示不正确的是[ ]

A.v(N2)=0.25 mol·L-1·min-1

B.v(H2)=0.75 mol·L-1·min-1

C.v(NH3)=1 mol·L-1·min-1

D.v(N2)=0.5 mol·L-1·min-1

考点:化学反应速率的计算
题型:不定项选择题

胃癌最常发生的转移途径是()

A.直接蔓延

B.血道转移

C.种植转移

D.淋巴道转移

E.沿肠管转移

题型:不定项选择题

Part 4


Questions 26-45


·Read the following passage and decide which answer best fits each space.
·For questions 26-45, mark one letter A, B, C or D on the Answer Sheet.
Participation (26) high school sports is not a constitutional right. (27) , it is a privilege, paid for by taxpayers, open to students who promise to (28) certain conduct requirements on and off the field. One of these promises is to (29) from using drugs. Drug use is a serious problem among high school students. Studies show that as many as 500, 000 high school students use muscle-pumping, life-destroying substances such as steroids. Many more use illegal drugs, (30) cause discipline problems and (31) the stage for lifelong (32) .
Drug testing works to (33) and identify use. That is why drug testing is required to compete in the Olympics, the National Collegiate Athletic Association and the National Football League. (34) drug testing was instituted by these organizations, use of performance- (35) drugs has been greatly reduced. We should want (36) in schools.
Indeed, many athletes (37) testing programs, and no wonder. Without testing, athletes have to choose between drug use and a competitive disadvantage (38) the field.
Those who challenge the need for drug testing may be forgetting (39) it is like be an adolescent. Peer pressure is enormous, and one of the few effective counter-weights is the fear of being caught. More importantly, once drug use is (40) , a school can (41) to the student before he or she gets addicted or arrested.
For 25 years, public schools (42) by federal judges and civil libertarians, with results everyone can see. It is time (43) decisions on how to run public schools locally (44) officials. There is nothing unconstitutional about asking those who gain the advantages of school-sponsored athletics to contribute to the safety of other players, the integrity of the game and their own well-being. The Supreme Court should leave these programs (45) .

A.Since

B.After

C.When

D.While

题型:不定项选择题

在“验证牛顿第二定律”实验中,在保持拉力F=5N不变时,某同学根据测出的数据,画出图线如图。但该同学未标注横坐标所对应的符号,请你在图中括号处补全。

题型:不定项选择题

共同参与型和指导合作型医患关系日益成为占主导地位的医患模式,说明医患关系呈()

A.民主化趋势

B.物化趋势

C.法制化趋势

D.分化趋势

E.商品化趋势

题型:不定项选择题

下列叙述中不属于全口义齿上颌尖牙排牙要求的是()

A.颈部向唇侧突出

B.与邻牙接触松

C.颈部稍向远中倾斜

D.远中转向腭侧

E.牙尖在平面上

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