Duas circunferências C e C' com raios R e R' são tangentes exteriores. Uma reta t é tangente comum externa às duas circunferências nos pontos A e B. O comprimento do segmento AB, onde A é ponto de tangência de C e B é ponto de tangência de C', é:

Um jovem saiu de um ponto A e caminhou 16 km para o norte. Depois andou 12 km para o leste, 8 km para o sul e 6 km para oeste, e chegou ao ponto B. A distância entre os pontos A e B é de:

Classify the verb in the following sentence: The news made me happy.

Give the function of the underlined words: The citizens elected Bush President.

We were sure we were going to the train, but we didn't, actually.

Rewrite the following sentences so that they have the same meaning. 1 - Perhaps he hasn't received our letter. 2 - I've never read such an interesting book. 3 - We've been lent some money by my wife's parents. 4 - "You stole the money", I said. 5 - The flight was so long that we had three meals on board.

Read the sentences below. Which sentence expresses which view? 1- I'm giving up work tomorrow. 2- I imagine Jack will win the championship. 3- I'm going to retire when I'm about 55. 4- That must have been George. 5- Can I borrow your pen for a moment?

Timothy was at school. His parents were well , but they were divorced. Timothy in the habit of pushing children no apparent reason, and on occasion he scratched a boy's leg until it .

Teaching is an activity which is directly or indirectly, by human beings human beings.

Teaching developing countries brings it many and rewards.