Cho (O; 6cm) và đường thẳng a. Gọi d là khoảng cách từ tâm O đến a. Điều kiện để a cắt (O) là:

A. Khoảng cách d < 6cm

B. Khoảng cách d = 6 cm

C. Khoảng cách d ≤ 6cm

D. Khoảng cách d > 6 cm

Có người cho rằng bình luận chẳng qua chỉ là sự kết hợp của hai kiểu lập luận giải thích và chứng minh. Nhận xét ấy đúng hay không đúng? Vì sao?

There are several heritage and splendid sights in Vietnam. Especially, Da Nang is one of the most popular place for both Vietnamese and foreign tourist. Da Nang includes sea, Son Tra island, mountain and beautiful landscape. There are a lot of interesting places such as: Asia entertainment park, Ba Na hill, Hoi An ancient town, My Khe beach, museum of art as well as famous bridges. The city is well known for its fresh atmosphere, friendly people and security. The weather is glorious all the year and it brings this city many delicacies from sea and perfect living condition for people, specifically the elder. Visiting Da Nang, I am really impressed by Ba Na hill containing longest cable car from land to the top of the mountain. It is an unforgettable experience for visitors to observe breathtaking sight and picturesque scene. Beside, the beaches have long golden sand, deep blue sea in addition huge bunches of fresh coconut. Tourist has a chance to relax, enjoy the peace and nature, play aquatic sport. Moreover, the city has many big bridges like: Dragon bridge, Quay bridge and a large outdoor entertainment named Asia park. Additionally, there are a lot of delicious typical dishes such as: Quang noodle, xeo cake, pork pan-cake and others. Da Nang is preserved for its natural beauty; therefore, there is an increasing number of tourists come here. Consequently, it leads to polluted environment, natural damage and other social problem. However, the security of the city is good that there is no street robbery. Hence, Da Nang is voted to be one of the most worth-living cities in Vietnam. In the future, I hope Da Nang will develop and become more popular over the world.

\(\frac{4\left(3x-2y\right)}{16}=\frac{3\left(2z-4x\right)}{9}=\frac{2\left(4y-3z\right)}{4}=\frac{12x-8y+6z-12x+8y-6z}{16+9+4}=\frac{0}{29}=0\)

\(\Leftrightarrow3x-2y=0\Leftrightarrow\frac{x}{2}=\frac{y}{3}\)

\(\Leftrightarrow2z-4x=0\Leftrightarrow\frac{x}{2}=\frac{z}{4}\)

\(\Leftrightarrow\frac{x}{2}=\frac{y}{3}=\frac{z}{4}\)

\(\Leftrightarrow\frac{x}{2}=\frac{y}{3}=\frac{z}{4}=\frac{2x+4y+5z}{4+12+20}=\frac{8}{36}=\frac{2}{9}=\frac{2x+3y-z}{4+12-4}\)=> A= 2x+3y -z = 12.2/9  =8/3

I have no more free time, I usually over head and ears to learn on class. But I always find free time to relax. I have special like on weekend. When I and my friends go to have coffee, or go to open-air relax centre to play sport as tennis, volley ball, kung fu, or even swimming. I occasionally play online game, but It is not more attractive than open – air activities, sport. Some time we have going picnic to where have much beauty landscape, act exchanges with friend make me satisfied. Learning some time make me stressful therefore recreational activities that make me more comfortable very much, and then I learn more fervent.

There are many outdoor games. However, among all the outdoor sports, football is my most favourite game. This game is famous all over the world. Football is a game played by eleven players on each side. There is one referee and two linesmen. In India football is played with great fervour. Even though we do not qualify for the World Cup matches, people here are quite passionate about this wonderful game. In Kolkata there are many football grounds. Among them Salt Lake Stadium is very big and well-known all around the world. I play football in my school. I am part of the school primary team. I am a supporter of Mohan Bagan Athletic Club, which happens to be the oldest club in Kolkata. I am also a devoted supporter of Brazil. Brazil won the soccer world cup for five years. Large number of spectators comes to see football matches. This game is a physical game and played mainly with the legs and head. Only the goalkeeper is allowed to catch the ball with his hands. Football, because of the thrill and excitement it offers, is my most favourite game.

B. cultural

1. ____the longest___

2. ____to drink___