四种写法
✔ 副词/介词词组/非谓语结构,独立句子
解析:逗号连接句首的副词/介词词组/非谓语结构和后面的独立句子。
Since then [,] so many other examples have been discovered that it no longer makes sense to say that evolution is as good as irreversible. (例子出处:剑10T4R)
✔ 主语, 副词/介词词组/非谓语结构,谓语及句子其他成分
解析:双逗号隔开句中的副词/介词词组/非谓语这三类结构。
The International Institute of Noise Control Engineering [,] on the advice of the World Health Organization [,] has established an international working party.’(例子出处:剑9T2R)
✔ 独立句子, 副词/介词词组/非谓语结构
解析:逗号连接部分句末出现的副词/介词词组/非谓语结构。
The gender difference is smallest at the level of Bachelor’s degree[,] however. (例子出处:剑4T3WT1)
✔ 名词,同位语,句子其他成分或者名词,同位语。
解析:句子中名词后面的同位语,用双逗号隔开其与句子主干;如果是句末名词的同位语,句末自然句号落尾。
Clemmons contacted Morteza Gharib [,] aeronautics professor at the California Institute of Technology. (例子出处:剑7T4R)