题目

Norman Bethune is one of China’s most famous heroes, but he wasn’t Chinese—he was Canadian. He gave his life to helping Chinese people.Norman Bethune         born in 1890. He became a         in 1916, and he went to the front to look after injured soldiers in the First World War. He saw many soldiers die in the war. Later he invented new treatments to         soldiers, and medical tools to use outside hospitals. In 1938 he came to China to treat the Chinese soldiers in the mountains north of Yan’an. There were         doctors, so he had to work very hard下列关于制备牛肉膏蛋白胨固体培养基的叙述，不正确的是A．操作顺序为计算、称量、溶化、倒平板、灭菌B．将称好的牛肉膏连同称量纸一同放入烧杯C．待培养基冷却至50℃左右时进行倒平板D．待平板冷却凝固约510 min后将平板倒过来放置