题目

Would you like to spend your vacation traveling by balloon（气球）？The first balloon trip took place in France in 1783. It lasted only eight minutes.    About a year later .An American and a Frenchman decided to cross the channel.(海峡) They discovered a hole in the balloon .It grew bigger and bigger ，the gas keeping the balloon up was escaping (giving off ), so the men threw all their belongings (财物) into the water to make the balloon lighter . It started to rise higher again , but it was still too close to the water. Finally the men threw away most of their clothes to 下列物质在氧气中燃烧，火星四射，生成黑色固体的是 [　　] A． 木炭 B． 镁条 C． 红磷 D． 铁丝