Biodiesel is a liquid fuel for diesel engines, but it is not pumped from oil wells. It is made from vegetable oil or animal fat — used cooking oil, soybean oil, and so on.

Biodiesel生質柴油is a liquid fuel for diesel engines是柴油引擎用的液態燃料，but it is not pumped from oil wells但它不是從油井抽出來的。It is made from它是用vegetable oil or animal fat植物油或動物油脂做的——used cooking oil, soybean oil, and so on像用過的食用油、大豆油之類的。

You can often put it in a diesel bus or truck instead of ordinary diesel, or mix the two.

You can often put it in a diesel bus or truck你常常可以把它加進柴油公車或卡車，instead of ordinary diesel來取代一般柴油，or mix the two或是把兩者混著用。

It is a technical and news word, not a kitchen word.

It is a technical and news word它是個技術性、新聞用的字，not a kitchen word不是廚房裡會用的字。

Though actually, bio here means “made from plants or animals”, not “harmless” and not “always better”. Growing the crops, cleaning the oil, and burning the fuel still affect the air and the land.

Though actually不過事實上，bio here means這裡的bio指的是"made from plants or animals"「用植物或動物做的」，not "harmless"而不是「無害」，and not "always better"也不是「一定比較好」。Growing the crops, cleaning the oil, and burning the fuel種植作物、精煉油、燃燒燃料，still affect the air and the land還是會影響空氣和土地。

It also is not the same thing as petrol (gasoline), and it is not the same as biogas, which is a gas, not a liquid.

It also is not the same thing as它也跟petrol (gasoline)petrol（汽油）不一樣，and it is not the same as而且也跟biogas沼氣biogas不一樣，which is a gas, not a liquid因為那是氣體，不是液體。