Simple Scientific Experiment（实验）
Below is a description of a single scientific experiment. It shows us how iron(铁) reacts (反应) with air and with water. Aim: To find out if iron rusts(生锈) (a) in dry air; (b) in water that has no air in it (air-free water) ; (c) in common water. Materials: Some clean iron nails(铁钉) ; test tubes(试管); test tube holder; cotton wool; oil; Bunsen burner. | |
Iron in dry air Method (1) Put some iron nails at the bottom of a test tube. (2) Push some cotton wool down the tube. (3) Leave the tube for one week. Result After one week, the nails have not rusted. Conclusion Iron does not rust in dry air. | (4) Add some oil to the water. (This will keep air out of the water.) (5) Leave the tube for one week. Result The nails do not rust in the tube with air-free water. Conclusion Iron does not rust in air-free water. |
Iron in ordinary water Method (1) Half –fill a test tube with water and add two or three clean nails. (2) Leave the tube for one week. Result The nails rust in the tube with common water. Conclusion Iron rusts in common water. | |
Iron in air-free water Method (1) Half-fill a test tube with water. (2) Boil the water for three minutes. (This makes sure there is no air in the water.) (3) Put two or three clean nails in the water. | |
1.In the first part of the experiment the cotton wool is most probably used to _______.
A. keep the air dry B. keep the tube wet
C. make the nails rust D. keep the tube clean
2. What are necessary steps to make sure the water in the tube is air-free?
① Leave half a tube of water in it.
② Boil the water for some time.
③ Put some clean iron nails in the tube.
④ Add some oil to the water.
A. ①② B. ①③ C. ②③ D. ②④
3.We can know from the experiment that only _______ makes iron rusty.
A. dry air B. cotton wool C. common water D. air-free water
完形填空 先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。（本大题共10小题，每小题1分，共10分）
Making friends is a skill like most skills. It practice. If you want to meet people and make friends, you must be willing to some action. You must first go where there are people. You won’t make friends staying home alone. Joining a club or a group, talking with those who like the same things as you do is much easier. Or join in some activity.
Many people are nervous when talking to new people. After all, meeting strangers means facing the unknown. And it’s human nature to feel a bit about unknown. Most of our fears about dealing with new people come from doubts about . We imagine other people are judging(判断) us, finding us too tall or too short, too this or too that. But don’t forget that they must be feeling the same way. Try to accept yourself you are, and try to put the other person at ease(舒适). You’ll both feel more comfortable.
Try to act self-confident even if you don’t feel that way. When you a room full of strangers, such as a new classroom, walk straight, look directly at other people and smile. If you see someone you’d like to to, say something. Don’t wait for the other person to start a conversation.
Just meeting someone does not mean that you will make friends with that person—friendship is based on mutual(互相) likings and “give and take”. It takes time to .
1.A. costs B. needs C. spends D. wants
2.A. take B. make C. do D. carry
3.A. everyone B. someone C. anyone D. nobody
4.A. unhappy B. uncomfortable C. unlucky D. unusual
5.A. yourself B. himself C. yourselves D. ourselves
6.A. like B. as C. what D. that
7.A. come B. go C. enter D. step
8.A. speak B. discuss C. say D. call
9.A. old B. young C. poor D. new
10.A. develop B. start C. keep D. change
--- How did you find your visit to Dalian, Joan?
--- ________.
A. Oh, wonderful indeed
B. I went there alone
C. First by train and then by ship
D. A guide showed me the way
Mike would rather ________emails to friends while John prefers________ phone calls.
A. write; to making B. write; to make
C. writing; to make D. to write; making
Put it down, Kitty. You mustn’t read ________letter.
A. someone else’s B. anyone’s else
C. anyone else D. anyone else’s
She has very________ close friends so that she really doesn’t know________.
A. a few; who to talk to B. few; who to talk to
C. little; what to do D. a few; how to do it
