※ 引述《tucson (tucson)》之铭言：
: ※ 引述《scju (QQ)》之铭言：
: 关键点在于"词性"/文法脚色
: As/than 当连接词时，其后可以省略
: 1. 主词+ 动词 (主词语动词与主要子句一样。Weather = it)
: The weather isn't as good as last year. (= as it was last year.)
: 2. 省略动词，保留主词(与主要子句的主词不一样，但动词与主要子句的动词一样)
: I found more blackberries than you. (= than you found.)
: : 特别是这两句：
: : The weather isn't as good as last year. (= as it was last year.)
: 理由同上
: : He worries more than is necessary. (NOT ... more than it/what is necessary.)
: 这句的than是当主词后面当然接动词is (至于为何用is 不用are这点我不清楚
现在有一个疑惑是，虽然知道than当主词时（即准关系代名词），
后面的原本的主词就省略了，但问题在于，我们如何能知道than当准关系代名词的
时机呢？
譬如上述这句：He worries more than is necessary.
照理讲是省略的那个主词和前面有重复，所以才能省略，那么以这句来说，重复的
部分的是什么呢？目前有看到以下两种说法：
1. He worries more than (he) is necessary (to worry).
2. He worries more than (the worry that) is necessary.
看起来是第一句比较合乎这个原则，he、worry确实都有重复，
可是我比较喜欢第二句的写法，但第二句的worry前面却并没有出现？
再来，https://www.collinsdictionary.com/dictionary/english/digest
有这样的写法：
digest
N-COUNT
A digest is a collection of pieces of writing. They are published together in
a shorter form than they were originally published.