Gọi
A = 44…4 có 2n chữ số 4
B = 22…2 có n + 1 chữ số 2
D = 88…8 có n chữ số 8
Ta có
A = 4(10^(2n−1) + 10^(2n−2) + … + 1)
B = 2(10^n + 10^(n−1) + … + 1)
D = 8(10^(n−1) + … + 1)
Nhận thấy
10^(2n−1) + … + 1 = (10^n + … + 1)(10^n − 1)/9
Biến đổi và quy đồng, rút gọn được
C = A + B + D = (2(10^n − 1)/9 + 1)^2
Vì biểu thức có dạng bình phương của một số tự nhiên nên
C là số chính phương.
Khoanh vào đáp án đúng
1.Today it's hot and sun/sunny.
2.There's a lot of raining/rain.
3.It's snowing/snow in the mountains.
4.At the beach it's very windy/wind today.
5.We can't go out. It's raining/rain.
6.There's a lot of wind/windy in the mountains.
7.Let's go to the beach. It's a beautiful sunny/sun day.
8.It's very cloud/cloudy today.
9.There's no snow/snowy in the jungle.
làm nhanh giúp mik nhé! mik cảm ơn
Viết các ngày sau sang tiếng Anh
1. Ngày 01/09 ⇒ the_____________________
2. Ngày 11/03 ⇒ the _____________________
3. Ngày 15/12 ⇒ the _____________________
4. Ngày 20/11 ⇒ the _____________________
5. Ngày 26/02 ⇒ the _____________________
6. Ngày 13/08 ⇒ the _____________________
7. Ngày 02/04 ⇒ the _____________________
8. Ngày 30/01 ⇒ the _____________________
9. Ngày 22/05 ⇒ the _____________________
10. Ngày 27/07 ⇒ the _____________________
11. Ngày 12/10 ⇒ the _____________________
12. Ngày 03/06 ⇒ the _____________________
Nối cột A với cột B
| A (Subjects) | B (What you learn in that subject) |
|---|---|
1. Mathematics 2. History 3. English 4. Physical education 5. Geography 6. Vietnamese 7. Information Technology 8. Science |
a. study what happened in the past b. speak a foreign language c. do exercise and learn to play sports d. read and write Vietnamese e. learn how to use the computer f. study the world’s weather g. learn about numbers and shapes h. study basic things about human and the environment |
Nối cột A với cột B
| A | B |
|---|---|
1. Would you like some orange juice? 2. What does Max look like? 3. What does your mother do? 4. What time is it? 5. What is your nationality? 6. Is he a doctor? 7. Who is tidier, Bing or Clara? 8. Do you like bread? |
a. It’s half past eleven. b. Yes, please. c. Clara is tidier. d. No, I don’t. e. I’m Vietnamese. f. He is tall. g. No, he isn’t. h. She is a nurse. |
Nối cột A với cột B
| A | B |
|---|---|
1. What are you doing? 2. Would you like some milk? 3. Let’s go to the school. 4. Why does she go to the post office? 5. What does he look like? 6. When is your birthday? 7. Do you like writing poems? 8. What subject do you have today? |
a. Yes, let’s. b. I’m reading a magazine. c. He is short. d. No, thanks. e. It’s on May 20th. f. Because she wants some envelopes. g. I have History and Math. h. Yes, I do. |
Nối cột A với cột B
| A | B |
|---|---|
1. Why does she like monkeys? 2. Let’s go to the zoo! 3. Would you like a drink? 4. What day is it today? 5. What animal does he want to see? 6. Can tigers run? 7. Which animal is bigger, an elephant or an ant? 8. What can a kangaroo do? |
a, It’s a good idea. b, Because monkeys is funny. c, It’s Monday. d, It can jump. e, Yes, they can. f, No, thanks. g, He wants to see crocodiles. h, An elephant is bigger than an ant |
chuyển các số đếm sau sang dạng số thứ tự
1. three ⇒ _____________________
2. nine ⇒ _____________________
3. twenty ⇒ _____________________
4. six ⇒ _____________________
5. twelve ⇒ _____________________
6. one ⇒ _____________________
7. thirty-one ⇒ _____________________
8. seventeen ⇒ _____________________
9. two ⇒ _____________________
10. twenty-three ⇒ _____________________
11. fifteen ⇒ _____________________
12. eight ⇒ _____________________
13. five ⇒ _____________________
14. eleven ⇒ _____________________
15. twenty-four ⇒ _____________________
16. ten ⇒ _____________________
17. seven ⇒ _____________________
18. twenty-eight ⇒ _____________________
19. fifteen ⇒ _____________________
20. thirteen ⇒ _____________________
Chọn từ khác loại:
4. A. fast B. noisy C. Slowly D. quietly
5. A. kind B. gentle C. clever D. ghost
I’m Peter. I’m in (1) ________________ 4D. I am a student of Newton primary school. My favourite (2) ________________ is English. I often have English on Monday, Tuesday (3) ________________ Friday. Learning English (4) ______________ very interesting. In an English lesson, we learn how (5) ________________ listen, speak, read and write English. Ms. Clara is (6) ________________ teacher. She is (7) ________________ England. She teaches us (8) ________________ lot of exciting things about England. I love her so much.
Question 8
A. a
B. an
C. the
D. X
Điền từ thích hợp vào đoạn văn
| In | and | years | name |
|---|---|---|---|
| are | an | my | housewife |
I am Ping. There (1) ___________ four people in my family: my father, my mother, my sister (2) ___________ me. My father’s name is Peter. He is 42 (3) ___________ old. He is an engineer. He works in (4) ___________ office near my house. My mother’s (5) ___________ is Jane. She stays at home to take care of the family, so she is a (6) ___________. My sister and I are both students. She is (7) ___________ grade 8 and I am in grade 4. I love (8) ___________ family.
