We()at anchor in the roadstead till the evening. ["have to ride","have to get","have to put","have to make"]
石油焦按照外形和质量不同,可分为哪几类?
下面的市场调研方法中不属于调查法的是()。 ["电话询问法","邮寄询问法","观察法","留置问卷法"]
检验煅烧程度的主要手段是什么?
写作是对于各种()的传播。 ["新的高尚的情感","新的思想","新的观点","新的进步的价值观念"]
前置胎盘的处理原则是什么?