迷宫密封是液相介质的主要密封类型。
正确
错误

单项选择题Questions 5 to 8 are based on the conversation you have just heard。A.He wants to change his job assignment。B.He is unhappy with his department manager。C.He thinks he deserves extra pay for overtime。D.He is often singled out for criticism by his boss。

单项选择题视图是一种常用的数据对象，它是提供( )和( )数据的另一种途径，可以简化数据库操作 A、插入，更新 B、查看，检索 C、查看，存放 D、检索，插入