题目

下列说法正确的是( )。 A．CO具有可燃性故可用于冶炼金属  B．塑料属于天然有机高分子材料 C．洁净的空气属于纯净物        D．N2化学性质稳定，故食品包装时充氮以防腐 答案：DIn Malta, people hold a 【1】(tradition) festival called Gostra. They hold Gostra Festival every year to mark the feast day of Saint Julian. Part of the festival is a special competition. For 【2】 competition, people prepare a piece of round wood, 【3】 is about 10 meters long. Then, they put oil over the pole and carry it to a boat, 【4】 one end on the boat and the other over the water. There are flags 【5】 (attach) to the end of the pole. People are supposed to take turns to run along the pole and get one flag at a time. Obviously, it is not easy to make it. Many people fall into the water and end 【6】(they) chances. The one who gets the most 【7】(flag) wins the competition.For some competitors, the style in which they fall off the pole seems to be 【8】(slight) more important than getting the flags. But there are still some others who show definite determination while 【9】 (run) on that oily pole. Following the day’s entertainment, as dusk 【10】(fall), hunters fire guns over the harbor to show respect for Saint Julian.