瓦斯电闭锁保护是在综采工作面安装()对瓦斯浓度自动监测,当瓦斯浓度超标时,能自动切断工作电源。
参考答案:瓦斯传感器
证券金融公司不得为他人的债务提供担保。()
—What's your father?
— ____. [ ]
A. He's working in Fukang.
B. He is always kind to others.
C. He is really a good man.
D. He's an engineer.