Here, the "in your current connection session" is important, which means the "PREVVAL" will only return the value that is generated in the same connection sessions.

这里，“在当前连接会话中”这一点很重要，这意味着“ PREVVAL ”将只返回在相同连接会话中生成的值。

youdao

Well-formed means there can be no overlapping elements, all elements must contain a closing tag, attributes must be quoted and given a value, and the case of the characters is important.

“形式完好”意味着不可以重叠(overlapping)元素，所有元素都必须包含关闭标签，而属性必须包含双引号和一个值，字母大小写也同样重要。

youdao

But there is little cause for taking the growth of GNP to be an end in itself, rather than seeing it as an important means for achieving things we value.

但是没有理由将GNP增长本身作为最终目标，而应该把它作为一种重要的手段，来完成我们所重视的事业。

youdao