关于叶酸下列不正确的是() ["不耐热","是DNA合成的必需营养素","人体自身可合成","存在于绿叶蔬菜、水果中","正常人每天需要200μg"]
年长儿多见,肺部体征常不明显() ["葡萄球菌肺炎","腺病毒肺炎","毛细支气管炎","支原体肺炎","支气管肺炎"]
现在开行的动车组轴距为()。 ["2650mm","2700mm","2750mm","2800mm"]
婴幼儿最常见的肺炎() ["葡萄球菌肺炎","腺病毒肺炎","毛细支气管炎","支原体肺炎","支气管肺炎"]
车钩监控回路通过机械到位行程开关和电气到位行程开关对车钩进行监控。
提高硅太阳能电池效率的方法有哪些?