is的词典解释
vi.
1.(用于第三人称单数现在时)是
The picture on the wall is beautiful.墙上的画很美。
Mr. Smith is a very good English teacher.史密斯先生是个很好的英语教师。
助词v.aux.
1.(与v-ing连用构成现在进行时;与v-ed连用构成被动语态)
Mr. Ward isknown as a great painter.沃德先生是一位遐迩闻名的大画家。
What is she doing over there?她在那儿做什么?
