It is not uncommon to require a second laser treatment should your eye pressure remain high after the first treatment. 如果第一次治疗后眼压仍然很高,则需要进行第二次激光治疗,而这种情况并不罕见。请问:这里的 should 是什么用法?谢谢!
Television,it is often said,keeps one informed about current events and the latest developments is science and politics.emmm后边的 is science and politics 这部分有点看不懂,前边不是已经有了keeps谓语吗?