A-A+
Fly ash can partly take the place of ______. A
问题详情
Fly ash can partly take the place of ______.
A. paving material
B. cement
C. concrete
D. the coal by-product
参考答案
正确答案：B
答案为B。根据第一段倒数第二句，and can replace up to 20 percent of the cement used in concrete, "replace"相当于“take the place of”
