A-A+
What is a by-product of burned coal？A. Aluminu
问题详情
What is a by-product of burned coal？
A. Aluminum, silicon, and magnetic.
B. Paving material.
C. Fly ash.
D. Concrete additive.
参考答案
正确答案：C
答案为 C。根据题干找到第一段第三句， two kinds of ash by-product are produced： a heavy bottom ash and a fine-as-powder fly ash符合题意。
