Nitrates are used as preservatives in food processing.

硝酸盐在食品加工中被用作防腐剂。

Nitrates are chemicals that occur naturally in water and the soil.

硝酸盐是水和土壤里天然存在的化学物质。

Nitrates leach from the soil into rivers.

硝酸盐由土壤渗入江河。

Bone meal and nitrates are common fertilizers.

粉和硝酸盐是普通的肥料。

Our water supply is becoming polluted with nitrates.

我们的水源正受到硝酸盐的污染。