问题 实验题

(1)化学是一门以实验为基础的学科,下列实验操作的描述中,正确的是____(填序号)。

①为使稀硫酸和锌制取氢气的速率加快,可向稀硫酸中加入用铜丝网包裹的锌粒

②用托盘天平称取10.4g食盐时,将食盐放在右盘中的纸片上称量

③配制一定物质的量浓度的溶液时,容量瓶洗涤后不用进行干燥

④以酚酞作指示剂,用标准浓度的盐酸滴定NaOH溶液,待溶液变成浅红色时即停止滴定

⑤测定溶液的pH时,用洁净、干燥的玻璃棒蘸取待测溶液,点在试纸中部,待变色后与标准比色卡对照读数

(2)下列说法中,符合安全要求的是____ (填序号)。

①在通风橱内做铜与浓硝酸反应的实验

②实验中剩余的过氧化钠粉末用纸包裹好后,放入垃圾桶内

③闻氯气的气味时,用手轻轻在瓶口扇动,仅使极少量的氯气飘进鼻孔

④为了节约时间,锌与稀硫酸反应一开始有氢气放出,就直接做氢气点燃实验

答案

(1)①③⑤

(2)①③

阅读理解

阅读理解

     Teachers have long said that success is its own reward. But these days, some students are finding that

good grades can bring them cash and luxury gifts.

In at least a dozen states this school year, students who bring home top marks can expect more than just

thankfulness.

     The most ambitious experiment began in September, when seven states - Arkansas, Alabama,

Connecticut, Kentucky, Massachusetts, Virginia and Washington-won spots in an Mobil-funded

program that, in most cases, pays students $100 for each passing grade on advanced placement (AP)

college-prep exams.

     It's an effort to get low-income and minority students interested in the courses, says Tommie Sue

Anthony, president of the Arkansas Advanced Initiative for Math and Science. "We still have students

who are not sure of the value, who are not willing to take the courses," she says. "Probably the motivation will make a difference with those students."

     Gregg Fleisher of the National Math and Science Initiative, which runs the seven-state program, says

the effort is modeled on a program adopted by Dallas in the 1995-96 school year that saw AP

course-taking jump obviously. That program is now statewide.

     While many educators would be against offering kids cash for good grades, Fleisher and others say

the idea is simple: "It's an encouragement to get them to basically make the right decision and choose a

more strict class," he says. "This teaches them that if they work at something very hard and have a lot of

support, they can do something they didn't think they could do."

     An analysis of the Texas program last month by Cornell economist C. Kirabo Jackson found that it

linked to a 30% rise in the number of students with high SAT and ACT scores and an 8% rise in

college-going students.(Notes: 1.SAT: 美国学术能力评估考试;2. ACT: 美国大学入学考试.)

1. What does the passage mainly talk about?

A. Success is its own reward.

B .A new motivation for students.

C. Good grades deserves gratitude.

D. Success makes a difference.

2. What's the purpose of the experiment?

A. To offer poor students luxury gifts on their birthdays.

B. To help poor students to keep on with education.

C. To get relatively poor students interested in their studies.

D. To make an effort to raise the value of money.

3. Which of the following statements is TRUE?

A. Students who top at college - prep exams get $ 100.

B. The program didn't have any effect on student's achievements.

C. The program has been going on half a dozen states this year.

D. The program was probably first adopted by Dallas.

4. According to the passage, the program         .

A. encourages students to study harder

B. makes everything possible

C. helps students choose right classes

D. teaches students to spend money

判断题