Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

For the last few years, my children have been going to a summer camp in northern Greece called Skouras Camp. They always seem to have a good time, so if you’ re wondering what to do with the kids for three weeks this summer, you could do worse than send them to this beautiful camp on the shores of the Aegean Sea. If your children, like mine, are keen on adventure, sports and good company, the Skouras Camp will keep them busy all day doing the things they most enjoy. Skouras is an international camp with children from all over the world. My children have made friends with children of their own age from Poland, China, Demark and the United States. Naturally, they get lots of opportunities to practise their English as this is the only language spoken. The camp is located in one of the most beautiful parts of Chalkidiki. It is huge (120.000 square meters) and is just a stone’s throw away from clear, blue Aegean Sea. It takes the children just five minutes to walk to the golden sandy beach on foot. The programme is packed with exciting activities such as horse riding and table tennis. Other sports in clude baseball, volleyball and athletics. The Camp ends with a sports contest in the last week which all parents are invited to attend.

The word contest in the last sentence could be replaced by ___________.

The amounts of oxygen and nitrogen in the air almost always