2. -1/11

343 cm3

Thi violympic nè mình làm rồi

À nhầm C mới là trạng. Sorry già rồi tay run chuyên gõ sai 

Câu này có verb rồi các chế còn chọn excel làm gì vậy. Mình nghĩ vẫn là nên chọn B đi 

1. My kitchen is as large as yours.

2. The buses in London are as clean as the buses in New York. (Or you can also say they are at the same hygience level) 

1. Because of the heavy rain, students are late for class

2. It is wrong of you not to help him study

3. Vietnam is one of the countries of the Asscociations of South East Asian Nations

4. Don't forget to keep in touch with us

5. How many hours a week do you spend on watching TV

6. It was a national holiday yesterday so my friends and I went on a picnic

7. It takes us an hour to get to the picnic site by motorbike 

8. I haven't see my grandfather since I left school 

9. I have waited for her for two hours but she has not come yet

10. I decided not to go to the movies with my friends last night because I have seen that movie before 

sorry nha câu 8 mình gõ lộn từ fix 

Ta có: abc = 100.a + 10.b +c = n^2 - 1 (1)
cba = 100.c + 10.b + a = n^2- 4n + 4 (2) 
Lấy (1) trừ (2) ta được:
99.(a – c) = 4n – 5
Suy ra 4n - 5 chia hết 99 
Vì 100 $$  abc $$ 999 nên:
100 $$ n^2 -1 $$ 999 => 101 $$ n^2 $$ 1000 => 11 $$ 31 => 39 $$ 4n - 5 $$ 119
Vì 4n - 5 chia hết 99 nên 4n - 5 = 99 =>  n = 26  =>  abc = 675
Thử lại thấy đúng. Vậy có một số tự nhiên có ba chữ số thoả mãn yêu cầu đề bài là 675 

Tick cho mình nha 

My family has 4 people: my father, my mother, my sister and I. My father is a great physical education teacher. Although my father is 45 now, he still maintain such a good figure. He is also very tall too which make him looks very strict as his real personality. My mother who is a principal of a primary school near our house is three years younger than my father. As a principal, she is very strict but also caring and thoughtful to her every students and me and my sister. She teaches us from the little things in life. Not only is she loved by us but also by her colleagues, her friends, our neighbours, our relatives,... and any others who has known her even in the first met. She is also said to be the most beautiful woman amongst her peers. My parents both received a lot of respect too. My sister is a pretty twentythree- year - old girl. In her appearance, we can easily find that she is the combination of my parents' beauty. She has got such a long black hair which is extremely straight and smoothly shinning. She always smiles and be kind to me. Even when I make mistakes, she tells me how to make it up instead of scolding. It is this amazing family that I love the most in my intire life. I am proud of being its member. Hence, I always try my best so that I would not let my parents down or bring bad remarks to my family.