The two theorems are proved that any ring can be extended into an algebraically closed ring and that the quaternionic skew field over a realclosed field is algebraically closed.
证明了任一环有代数封闭的扩张环，且实封闭域上的四元数体是代数封闭的，给出了代数封闭环的若干性质。
2
That is, the real database connections are closed relatively infrequently, but their pooled proxies are acquired and released with every transaction.
也就是说，真正的数据库连接会相对较少关闭，但它们的池代理则会随着每个事务获取或释放。
3
That means the easy way of devoting more resources to the frontline in Afghanistan - scrapping the big-ticket items that serve little real purpose - is closed off.