Read the text below and choose which answer (A, B, C or D) best fits each gap, numbered 1-8. The first one (0) is an example and is done for you.
Mars on Earth
The centre of Antartica, where winter temperatures frequently fall to (0) minus 80 degrees centigrade and for four months of the year there is (1) darkness 24 hours a day, is one of the most extreme environments on Earth. It is also by (2) the most similar place to the surface of Mars, which is why a (3) of thirteen scientists from the European Space Agency have spent nine months at a base there.
They have been studying the physical and psychological (4) on humans of living in extreme conditions, in order to obtain a better understanding of the difficulties humans will (5) during the long flight to Mars and their stay there. Of course, space is (6) Antarctica in that astronauts have to adapt to weightlessness, but the base is 3,200 metres above sea (7) making it difficult to breathe there - as it can be on space flights. They have also, like space travellers, experienced strong feelings of being (8) off from civilisation.
For questions 9-16, read the text below and think of the word which fits each gap best. Use only ONE word in each gap. There is an example answer for you at the beginning (0).
Marathon in the Mountains
The Ultra-Trail of Mont Blanc is an extreme marathon held annually (0) since 2003 in the mountains of France, Italy and Switzerland. Widely regarded (9) one of the toughest races in the world, the Ultra-Trail takes place in August, (10) temperatures frequently range from over 30 degrees Centigrade at the lowest points of the course, to well (11) freezing at the highest.
An Olympic marathon is 42.5 kilometres long, but (12) one is over 160 kilometres in length and includes nine mountain peaks. That involves climbing a total of approximately 9,500 metres (13) is considerably higher than Everest. In (14) of, or perhaps because of this, the annual event has become increasingly popular with runners, to (15) an extent that the numbers had to be limited to 2,300. Only about half of these, (16) average, are likely to finish the course, in times that typically vary from 20 hours to over 45.