白云石主要由CaCO3与MgCO3组成,品质判断依据MgCO3的含量评定。
参考答案:对
– We didn’t go to South Hill because of ____________.
-- What a pity!
A.it rained hard
B.it is rainy
C.it rains
D.the heavy rain
外向型人的主要特征有:()
A.灵活、开放
B.安全、规律
C.缜密、严谨
D.克制性强