懂你英语 Level 3 - Unit 2 - Part 1
Listening
States of Matter
Matter is made of atoms and molecules.
Water, for example, is the H2O molecule.
This means that a molecule of water has 3 atoms.
A water molecule has 2 hydrogen atoms and one oxygen atom.
Substances like sugar have many atoms in their molecules.
A molecule of sugar has many atoms, including carbon, hydrogen and oxygen.
Matter is made of molecules, such as H2O, which is the water molecule.
Matter can be in one of three states: solid, liquid or gas.
Water and ice are the same substance, but they are in different states.
These states depend on the temperature of the molecules.
When we heat a substance, the molecules move faster and try to take up more space.
When we cool a substance, the molecules move more slowly.
When we cool a substance to its freezing point, it becomes a solid.
In a solid, the molecules move very little.
Their positions are almost fixed.
To be fixed means that their positions don’t change.
If we heat the molecules, they move faster and away from each other.
The solid begins to melt, like ice cream on a hot day.
At a certain temperature, the solid begins to change into a liquid.
The temperature at which a solid changes into a liquid depends on the substances.
For water, the solid begins to change into a liquid when its temperature rises to above 0 degrees Celsius.
For some substances, such as steel, the temperature at which it becomes a liquid is much higher.
Steel often melts at around 1370 degrees Celsius.
If we continue to heat a liquid, the molecules move even faster.
At a certain temperature, the liquid begins to change into a gas.
For water, the liquid begins to change into a gas at 100 degrees Celsius.
That is the boiling point of water.
Inside a star, such as our Sun, the temperature is very high.
Everything inside the Sun is a gas.
According to scientists, there are over 65 elements inside the Sun.
These include oxygen and iron.
Over 90 percent of the Sun is hydrogen gas.
Tests Results
Yesterday there was an important science test.
Lisas, Tom and 20 other classmates took the test.
The test was about the states of matter and how they are different.
There were 25 questions on the test, and they had 45 minutes to take it.
Here are some of the test results.
Two students got perfect scores.
The lowest score was 68 out of a hundred.
The average score was 86.3.
Eleven students scored higher than average.
Eleven students had below average scores.
Tom missed two questions on the test, so his score was 92.
His score was the eighth highest in the class.
Lisa missed two and a half questions, so her score was 90.
Her score was the tenth highest score.
Her score was 4 points higher than the average score.
Lisa was disappointed with her test results.
She studied hard for the test, but she still didn't do well.
As a result, she plans to study harder for the next test.
The next test will be in about two weeks.
Tom was surprised and happy with his test results.
He didn't study hard, so his result was better than he expected.
He was also happy that he did better than Lisa did.
Tom was surprised and happy with his test results.
Vocabulary
Emotions
She is screaming because she is really scared.
Something is chasing her so she is screaming for help.
He is shouting because he is angry.
When hes really angry he often shouts like this.
She is sleeping because she's tired.
Last night she didn't get enough sleep, so today she has no energy.
She's crying because she's sad.
She got some bad news a few minutes ago.
She's smiling because she's happy.
Her boyfriend just called and he's returning from a long trip.
Hobbies
This man is hiking up a mountain trail.
He is wearing hiking boots and is carrying a pack on his back.
This man enjoys cooking.
He attends a cooking class once a week.
This woman enjoys gardening.
She grows flowers, such as roses, and vegetables, such as tomatoes, in her garden.
This boy loves playing games.
He likes all kinds of games, including this video game on his computer.
This old couple enjoys traveling.
They take several trips a year, often to different countries.
Dialogue
Ready for the Meeting
W: Oh, there you are, finally.
M: Yeah, I'm sorry.
W: Why are you so late? You were supposed to be here 30 minutes ago.
M: I got on the wrong subway by mistake.
W: Why didn't you call? I was really worried.
M: I don't have my phone. I left it in the office because I was in such a hurry to get here.
W: OK, well, you're here now. We don't have much time.
M: Yes, we'll have to hurry. The meeting starts in 15 minutes, right?
W: Yes, it's supposed to, if everyone gets here on time.
W: Did you read my presentation?
M: Yes, I do. It's good, but it's a bit too long. I'm afraid there won't be enough time for questions.
W: Do you have any suggestions?
M: Yes, I do. I think the company introduction can be cut in half. They know what we do.
W: OK, I won't show the video. It's about 2 minutes long.
M: That's a good idea. The video is on our website and is not that good any way.
W: Do you have any other suggestions?
M: No, I don't. I'm sure you're doing a great job. Are you ready?
W: Yes, I'm ready. The meeting room is on the 21st floor.
M: OK, let's go.
Discussing Test Results
Lisa: How did you do on yesterday's science test?
Tom: I did better than expected. How about you?
Lisa: I didn't do very well. I expected to do better than I did.
Tom: What was your score?
Lisa: I got a 90. What about you?
Tom: I got a 92. I only missed two questions.
Lisa: So you did better than I did. And I really study for it too.
Tom: That is a surprise. You usually do better than I do.
Lisa: Yes, I wasn't careful. I made one really stupid mistake.
Tom: What was it?
Lisa: I said 90% of the sun is Helium instead of Hydrogen.
Tom: Wow. That was a stupid mistake.
Tom: What was the average score for the class, do you know?
Lisa: The average score was 86.3 and the lowest was 68.
Tom: Do you know who got the lowest test score?
Lisa: No, I don't. I don't know who got the lowest score.
Tom: It's probably a secret. Did anyone get a perfect score?
Lisa: I think Ada and Sandi both got perfect scores.
Tom: Yes, they always do well. I wish I were as smart as they are.
