人山人海
1.a sea of people [faces]
2.huge crowds of people
3.the sea of humanity (in a crowd)
4.crowded conditions
例句：
1.早早的,街上已是人山人海了.
Early,the street is a sea of people.
2.广州火车站可说是人山人海.
The Guangzhou train station is a literally a sea of humanity.