-Do you konw who invented the telephone?

问题描述:

-Do you konw who invented the telephone?
-No.but it is really a most important useful invention.句中为啥用

这里没有之一的意思啊..楼上的同学,如果是it is one of the most improtant useful inventions.才是表达的之一吧.
这里只是因为invention是可数名词,你可以把所有形容词去掉,只剩主*分,就很好理解→It is an invention.所以这里的 a 只是为了表达invention是个可数名词哈~