人山人海----a sea of faces

例句：
A:How many people partcipated in the grand ceremony?
有多少人参加那场盛大的仪式？
B:Believe it or not, a sea of faces.
信不信由你，人山人海。

同义词：
huge crowds
a sea of people

注释：
partcipate in 参加
believe it or not 信不信由你