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.
