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
At the end of the meeting, it was announced that an agreement ______.
A．has been reached
B．had been reached
C．has reached
D．had reached
翻译句子。
1. Mary喜欢与她的朋友玩耍。
Mary likes ______ ______ ______ her friends.
2. 海豚对人们很友好。
Dolphins ______ ______ ______ people very much.
3. —你为什么不喜欢数学？
—因为它太难了。
—______ don't you ______ math?
—______ it is very ______.
