(on / in / by) the whole it's a good idea, but there are one or two
problems.
could you be quiet for a minute, please? i'm (at / in / on) the
phone.
jim managed to climb into the house (under / for / by) means of a
ladder he found
the company wants us to pay for the goods (on/in/at) advance.
- (under / in / af) the terms of the agreement you have to pay a
monthly rent.
- personally, i am (in/on/at) favour of banning cigarette smoking
completely! ​

1) Polar bears are classified as marine mammals because they spend most of their lives on the sea ice of the Arctic Ocean. 2) They have a thick layer of body fat and water-repellant coat that insulates them from the cold air and water. 3) Polar bears spend over 50% of their time hunting for food, but less than 2 % of their hunts are successful. 4) Their diet mainly consists of ringed and bearded seals because they need large amounts of fat to survive. 5) The total polar bear population is divided into 19 units or subpopulations. 6) The survival and the protection of the polar bear habitat are urgent issues for WWF(WorldWildlifeFund)

Christopher Columbus discovered America in 1492. He was born in Italy. His father and both grandfathers were cloth makers. Columbus was a seaman and made many sea voyages.

Most people in Columbus's days thought that the earth was flat and they did not believe that beyond the Atlantic Ocean lay India. In 1492 the King and the Queen of Spain gave him money to go to India. He decided to sail west as he was sure that our planet was round. There were 3 caravels: the Santa Maria, the Nina and the Pinta. After sailing 4000 miles he reached some land.

The crew saw something like a white cliff and cried out: "Tierra! Tierra!". Columbus thought 'that it must be India but it was not. It was a new land — a new continent. It was America. Columbus named the land they had reached San Salvador ("Holy Saviour"). People began to speak about the land as "The new World".

European people came to the New World for many reasons. Some hoped to find gold and silver. Priests and missionaries came to bring the Christian religion to the Indians. Among those who came for freedom was a small group of English people called Pilgrims. They wanted to start a new life and to have no religious problems they had in England.

In 1620 on the ship "Mayflower" they landed in the north-east of America. They set up a colony and called that part of the country "New England".