Read the text below. For each empty space (1-12) choose the correct answer (А, В, C or D). Recently scientists (1) more about life on planet Earth and now they (2) better where to look for life in outer space.
For a long time, scientists (3) that life (4) on sunlight for energy. Then, in 1978, a submarine (5) to the bottom of the Pacific Ocean. Although there (6) no sunlight, they (7) tube worms, clams and crabs, and other life forms.
Since then scientists (8) at the life on earth in other difficult environments — dry, cold and hot - and (9) that water is the key. Wherever there (10) water, life (11) exist. So scientists (12) to search for water in the solar system.

A В C D
1 found out has found out find out have found out
2 knew have known know known
3 believe believed believes have believed
4 depended depend depends have depended
5 dive have dived has dived dived
6 were was has been have been
7 have found finds found has found
8 have looked looked looks has looked
9 found have found has found finds
10 was has been is be
11 could will be able was able can
12 began has begun have begun begin

1. Literally, the name "Antarctica" means "opposite the bear." The ancient Greeks named the icy north "Arktikos" in honor of the Big Dipper, located at the North Pole.2. Officially Antarctica was discovered only in 1820, during the voyage of Russian naval expedition led by Thaddeus Bellingshausen and Mikhail Lazarev.3.Antarktika not belong to any State Although a few countries (including Australia, Argentina and the United Kingdom) at the time tried to claim the ownership of the Antarctic, it still remains free of the state space. In 1959 he was awarded "The Antarctic Treaty", proclaiming it "natural storerooms, devoted to peace and science." The agreement was signed by 48 states.4. Antarctica - the only continent with no time zones. Scientists found here live either in time of their homeland, either by time employees, supplying them with food and equipment.5. Antarctica - is not only the coldest place on Earth, but also the driest. Average rainfall in the Antarctic is only 10 centimeters. So-called McMurdo Dry Valleys - a place where the combination of cold and dryness reach the absolute. Rainfall was not here more than two million years! The surface and the climate of the area so reminiscent of the surface of Mars that NASA conducted tests of the space program is "Viking".6. However, despite its dryness, Antartika contains 70% of all fresh water reserves on the planet - of course, in the form of ice!7. The cold and dry - not only records of the continent. Here are the point of the strong and long the most powerful wind and solar radiation.8. The most "positive" record of the region belongs to the Antarctic Weddell Sea: it is considered the cleanest in the world. That, however, is logical: to pollute it is absolutely no one. The waters of the sea is so transparent that through them you can see objects that are at a depth of 80 meters!9. In Antarctica has no permanent residents only people who live in these inhospitable lands - scientists. In summer months, the number is about 5 thousand people. In winter, this figure drops to 1 thousand.10. By the way, most "old" month for Antarctica with the most warm weather - it's February. At this time, a change takes place, and scientists at the stations.

1. Antarctica is the windiest place on earth. 
2. Antarctica is the coldest continent. Temperatures in the winter can drop below –73°C.
3. Antarctica is the driest continent. it is almost entirely desert. Very little snow or rain falls on the continent, but because it is so cold, the small amount of precipitation that doe fall does not melt.
4. Antarctica has the highest average elevation of any continent. This is due to all the ice on it! 
5. Because it never rains in Antarctica, it is considered the world's biggest desert.