汽轮机启动有()方法。 ["A、全自动启动","B、半自动启动","C、手启动","D、混合启动"]
集市交易中最具民俗特点的是:() ["叫卖声","敲击声","中人的活动","店招"]
大型机组启动前,()会使汽轮机不能启动。 ["A、停车信号未复位","B、出口压力低联锁旁路","C、振值高联锁未复位","D、透平零转速"]
()条件未满足,机组不能启动。 ["A、盘车","B、无循环水","C、入口压力低报警","D、润滑油备用泵自启"]
天然气正常燃烧时的火焰颜色是()。 ["(A)红色","(B)淡蓝","(C)稍黄","(D)青蓝色,火焰尖端稍带黄色"]
为什么说被子植物比裸子植物更进化?