Bauxite is the primary source of aluminum.

铝土矿是铝的主要来源。

Waste is a primary source of pollution.

对非生物降解物的处理是污染的主要来源。

Disposal of nonbiodegradable waste is a primary source of pollution.

对非生物降解物的处理是污染的主要来源.

Carbon dioxide emissions are the primary source of greenhouse gases.

二氧化碳的释放是温室效应气体的主要来源.

However, salt added to processed foods is the primary source of dietary sodium.

但是食物加工过程中加入的盐是饮食中钠的最主要来源，

In addition, the fishing industry was a primary source of wealth in Massachusetts.

此外捕鱼业也是马萨诸塞一带财富的主要来源.

In addition, it was a primary source of essential food oil and protein for humans and animals.

此外，这是一个基本的食品油和人类和动物蛋白质的主要来源。

The tax, as the primary source of finance in a country, is considered as the price we pay for the civilized society.

而税收，作为国家财政收入的主要来源，在国外被人们认为是“文明社会公共服务的等价支出”。

We touched on this in a previous video, but it definitely worth repeating. Sunlight is your primary source of vitamin D.

我们在之前的视频中提到过这个，但它绝对值得重复。阳光是维生素D的主要来源。

Until very recently, the two largest pulp manufacturing groups on Sumatra used timber from natural tropical forest as the primary source of their pulpwood.

直到最近，苏门答腊岛上两个最大的纸浆生产集团还在采用天然的热带森林木材作为他们纸浆的主要来源。