【起止标识】标记非谓语动词短语时,一定是从动词不定式(to do)、动名词(doing)或分词(现在分词doing或过去分词done)开头,到以下四种情况终止。 ① 到句尾终止,如:Li Hui is a teacher (teaching English). ② 到句中的逗号终止,如:(To improve my English), I often l...