判断题 在齿轮箱、汽轮机或空气压缩机中常用电涡流传感器来监控主轴的径向振动。
单项选择题 下面四种岩石中,耐火性最差的是______。 A.石灰岩 B.大理岩 C.玄武岩 D.花岗岩
未知题型 What is the author's view on personality?A.Personality is the key to success in public speaking.B.Extroverts are better public speakers.C.Introverts have to learn harder to be good speakers.D.Factors other than personality ensure better performancE.