What's more, the chemical materials will do harm to our health.

而且，其包含的化学成分还会给我们的健康带来危害。

Over the past four years, he and his group of batik makers have changed from using chemical materials for dyes to mangrove-based products.

在过去的四年里，他和他的蜡染制造团队已经从使用化学材料制成的染料转变为用红树林制成的天然染料。

So the water and oxygen necessary for human survival could be produced using chemical materials that can be easily obtained from Venus's atmosphere.

因此， 人类生存所必需的水和氧气可以使用很容易从金星大气中获得的化学材料来生产。