高盐稀态发酵法（稀醪发酵法）的优点？
参考答案：
优点：（1）酱油香气好；（2）酱醪较稀薄，便于保温、搅拌及运输，适于大规模机械化生产。
---- Mr. Smith is said to have retired and he is living in the country now.
---- Yes. He ________ in our factory for 35 years! What a good worker!
A．had been working
B．had worked
C．worked
D．have worked
含碳量90%的无烟煤4kg（假设其它成分均不含碳元素）完全燃烧，理论上可得到二氧化碳多少千克？
