题目

    At the 1924 Olympic Games in Paris, the sport of canoe racing was added to the list of international competitions. The favorite team in the four-man canoe race was the United States team. One member of that team was Bill Havens. As the time for the Olympics neared, it became clear that Bill’s wife would give birth to their first child about the time that the US team would be competing in the Paris games. In 1924, there were no jet airliners from Paris to the Unites States, only slow ocean-going ships. Bill found himself in a dilemma. Should he go to Paris and risk not being at规范的操作是实验成功的前提，下列实验操作正确的是（ ）A. 实验完毕后，实验过程中剩余的试剂都应该放回原试剂瓶B. 蒸发饱和食盐水，蒸发皿必须放在石棉网上，用酒精灯的外焰加热C. 玻璃管与胶皮管连接时，应将玻璃管一端用水润湿，稍用力转动插入胶皮管中D. 没有腐蚀性的药品可直接放在电子秤上称量，有腐蚀性的应放在烧杯中称量 C 【解析】A、实验完毕后，实验过程中剩余的试剂不能放回原试剂瓶，因为会污染原瓶中的药品，错误；B、蒸发皿可以直接加热，不需要垫石棉网，错误；C、玻璃管与胶皮管连接时，将玻璃管一端用水润湿，稍用力转动插入胶皮管中，正确；D、没有腐蚀性的药品直接放在天平上称量会污染药品，应垫上一张纸，错误。故选C。