two questions,thanks!

britney_gao

1. the mississippi riverboat, which evolved from simpler steamship of the early 1800's, became the dominant form of passenger transport on the mississippi river.
前面的riverboat 是单数，后面的steamship 为什么用复数？？

2.the various peoples who developed north america have made it a world leader economic.
为什么peoples 加"s"?

Thanks

Diana

2.the various peoples who developed north america have made it a world leader economic.
为什么peoples 加"s"?
※※※※
people在这里的意思是“种族”，所以用复数。

britney_gao

thank Diana!
then how about the other question?

shiina

如果只讲simpler steamboat(单数)的话不合文法规定,
前面没有冠词或所有格
所以只能改为复数

个人浅见,还望各位指正

困难是弹簧

shiinaMM说得对。一般来说，可数名词要么前面有限定词，要么用复数。