Aplaneisamachinethatcanfly.(指一类人或事,相当于akindof)Aplaneis"a"machinethatcanfly.(指一类人或事,相当于akindof)InmanyplacesinChina,"the"bicycleisstillapopularmeansoftransportation.（表示某一类

Question

A plane is a machine that can fly.(指一类人或事,相当于a kind of)
A plane is "a" machine that can fly.(指一类人或事,相当于a kind of)
In many places in China,"the "bicycle is still a popular means of transportation.（
表示某一类人或物
）
这两句中 为什么第二句用“the”?不是也指一类物吗?

Answer 1

第二句你的subjective(主语) 是Bicycle(自行车) 用The是特指bicycle 这个主语,表强调中国很多地方主语（自行车）仍然一种流行的交通工具　;而第一句 a用在句首泛指,如a man who from　US　一个来自美国的男人而我们...