Question:
Read the text and answer the questions.
Many students are under great pressure this term. There is some advice on studying and preparing for exams. Sciences Ask students what is the most difficult course, and most of them will give you the same answer: mathematics. This is also true for Dai Shuang, a 14-year-old student at No.1 Middle School. He says, "It's so difficult that I get a headache whenever I think about the math exam." According to Dai, studying this course is not easy. He usually studies math by himself and spends most of his free time reading math books and doing exercises. _ Qin Xia, a math teacher, offers some advice. "Most students fear mathematics because they think the class is too difficult or boring." he says, "These students don't listen carefully in classes or even sleep." In Qin's opinion, they can try to take notes. And they'd better ask teachers for help. It's difficult for students to teach themselves math, which will waste a lot of time. Besides, doing a lot of exercises is also important. Arts Zhu Tianjiao, a 13-year-old student at Megan Middle School, is very nervous because she doesn't know how to improve her English. _ Xia Bingcong, a top student at Tsinghua University shares some of her learning experiences. According to Xia, memorizing, listening and reading are important in language learning. "Studying on a daily basis is the best choice." Xia says.
1. how old is Dai Shuang?
2. Where does he go to school?
3. Does he enjoy exams?
4. Why not?
5. Does he study with someone else?
6. Do the students pay attention in class?
7. Who is available to answer their questions?
8. Why is Arts Zhu anxious?
9. Does she go to school with Dai?
10. Where does she attend?

Numbered answers:
1. 14
2. No.1 Middle School
3. no
4. It's so difficul
5. no
6. no
7. Qin Xia, a math teacher
8. is very nervous because she doesn't know how to improve her English
9. no
10. Megan Middle School

Question:
Read the text and answer the questions.
CHAPTER VIII

A TIME OF WAITING

Dinah woke two minutes before one o'clock, and Nat at once lay down and, resolutely refusing to allow himself to think any more of the situation, was soon fast asleep.

"It am jess beginning to get light, Marse Glober," the negress said when, as it seemed to him, he had not been five minutes asleep. However, he jumped up at once.

"It is very dark, still, Dinah."

"It am dark, sah, but not so dark as it was. Bes' be off at once. Must get well away before dem black fellows wake up."

"How is Madame Duchesne?"

"She sleep, sah; she no wake for another tree or four hours. Dinah give pretty strong dose. Bes' dat she should know noting about it till we get to a safe place."

"But is there any safe place, Dinah?"

"Yes, massa; me take you where dey neber tink of searching, but good way off in hills."

Myra by this time was on her feet also.

"Have you slept well, Myra?"

"Yes, I have slept pretty well, but in spite of the two blankets under us it was awfully hard, and I feel stiff all over now."

"How shall we divide the things, Dinah?"

"Well, sah, do you tink you can take de head of de barrow? Dat pretty heaby weight."

"Oh, nonsense!" Nat said. "Madame Duchesne is a light weight, and if I could get her comfortably on my back I could carry her any distance."

"Dat bery well before starting, Marse Glober, you tell anoder story before we gone very far."
1. Who was asleep?
2. Who had just woken?
3. When did Dinah wake up?
4. Was Madame Duchesne still asleep?
5. How much longer did they think she would be asleep for?
6. Why were they so sure?
7. What were they plotting to do while she slept?
8. What skin color were they?
9. Where were they going?
10. Was it light out?

Numbered answers:
1. Nat
2. Dinah
3. two minutes before one o'clock
4. yes
5. three or four hours.
6. gave a strong dose
7. leave
8. black
9. a safe place
10. no

Question:
Read the text and answer the questions.
In chemistry, pH () (potential of hydrogen) is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH 7 (25C), being neither an acid nor a base. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively.

pH measurements are important in agronomy, medicine, biology, chemistry, agriculture, forestry, food science, environmental science, oceanography, civil engineering, chemical engineering, nutrition, water treatment and water purification, as well as many other applications.

The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Primary pH standard values are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen electrode and a standard electrode such as the silver chloride electrode. The pH of aqueous solutions can be measured with a glass electrode and a pH meter, or an indicator.
1. what does pH mean?
2. what kind of scale?
3. what does it specify?
4. what is it the negative of?
5. measured in what?
6. what are pH less than 7?
7. and more than 7?
8. what is water?
9. what degree?
10. Is it a water or a base?
11. Can pH be less than 10?
12. less than 0?
13. greater than 14?
14. What is used to measure the pH of aqueous solutions?
15. and what else?
Numbered answers:
1. potential of hydrogen
2. numeric
3. the acidity or basicity of an aqueous solution
4. the base 10 logarithm
5. moles per liter
6. acidic
7. basic
8. neutral, at pH 7
9. 25C
10. neither
11. Yes
12. Yes
13. Yes
14. pH meter
15. a glass electrode