A large, valved, brass wind instrument with a bass pitch.大型带活塞的低音铜管乐器.The French horn is the hardest wind instrument to learn.法国圆号是最难学的管乐器.Master Huang: Is it a wind instrument?黄师父: 它是管乐器 吗 ?...
1919至1920年的冬天斑疹伤寒症流行.A typhus epidemic struck in the winter of 1919–20.那就不必担心路上得坏血症或斑疹伤寒这类疾病了!No fear of scurvy or ship fever this voyage.那么医生是如何防止斑疹伤寒的扩散与传播的 呢 ?And how do doctors prevent the spread of typhus?...