焦油加工的主要任务是获得酚、萘、蒽等纯产品和()等粗产品。
参考答案:洗油沥青
The news that he failed in the exam _____________ his unhappiness this morning.
A.accounted for
B.accounting for
C.had accounted for
D.to account for
脊椎动物结构比无脊椎动物结构复杂,所以比无脊椎动物种类更多,分布的更为广泛.______.