题目内容:
Kieselguhr G consists of natural kieselguhr that has been extracted with hydrochloric acid and calcined,and to which adout 15% Of calcium sulphate hemihydrate has been added.上文中,“which”指代( )。
A.natural kieselguhr B.calcined kieselguhr
C.hydrochloric acid extracted Kieselguhr
D.Kieselguhr G
E.Calcium sulphate hemidydrate
参考答案:
答案解析: