公交的英文：
public transportation
mass transit

参考例句：

Greater Vancouver transit system
大温哥华公交运输系统

This development, which must make access to the bus, train, and subway easy and affordable, is urgent.
发展包括公交、火车和地铁的方便且充足的公交系统十分紧迫。

Try to use mass public transportation whenever possible, such as the subway or public bus.
试着尽可能使用公共交通系统，如地铁或公交巴士。

The economy has longstanding weaknesses, such as poor skills and a congested transport system.
经济长期疲软，就好像是不熟练的手艺和拥挤的公交系统。

Recommend regulations that would support public transportation without discriminating against private transportation.
给出一些既支持公交又不歧视私人交通的建议措施。

Kunming has already enjoyed BRT, and Pudong will be building a system soon.
昆明已经采用了快速公交系统并身受其益，上海浦东也将很快上马。

She commutes from her home in the suburbs to her office downtown
她每天在郊区的家和市中心的办公室之间乘公交车辆上下班。

public是什么意思：
adj. 公众的；公共的，公用的；政府的；公然的，众所周知的
n. 公众，民众；大众，群众

public administrator
公定遗产管理人

Public law includes laws that affect the public generally.
公法一般包括影响公众的法律。

The press will give publicity to the fact.
出版社将把事实真相公诸于世。

transportation是什么意思：
n. 运输，运送；流放；运输工具

To transport by boat.
用船运输

transportation leakage
运输漏损量

He was sentenced to transportation for life.
他被判处终身流放。

mass是什么意思：
n. 团，块，堆；大量；群众；大部分，主体
v. 集中，聚集
adj. 大众的；大规模的

a mass murderer
杀戮众多的人

stability of rock mass and soil mass surroundingunderground excavation
地下洞室围岩(土)稳定性

A mass or collection of material that is distinct from other masses.
和其它大多分开的一团和一堆物质。