One problem is that even though the raw materials used in industrial biotechnology may not be derived from fossil fuels, they are still capable of stirring up some difficult ethical questions.
其中的一个问题是，尽管工业生物技术中使用的原材料不来自矿物燃料，但仍会引起难以解决的道德问题。
2
How long can we continue to supplement agroecosystems with energy derived from declining fossil fuel supplies?
由于矿物燃料供应量下降，我们供应农业生态系统能量能持续多久？
3
A crystalline compound, C18H 18, derived from pine tar, fossil resins, and tar oils.