决定材料对X射线吸收量最重要的因素是()
A.材料厚度
B.材料密度
C.材料原子序数
D.材料晶粒度
参考答案:C
Write out the answer. 这是一道应用题,请列式解答,并写出答语。
Three cats are hungry. The yellow cat wants to eat twenty-one little fish. The white cat wants to eat twenty
little fish. The black cat wants to eat thirty-one little fish. How much fish do they want to eat?
1. 列式解答:
2. 写出答语:
简述半官方机构的功能。