用“pollution free”造句大全，pollution free造句

Trunk inoculation of Shudaifu was long lasting, pollution free, safe to natural enemies and no pesticide residue in fruits. It could be popularized in the production.

The inserting pin with fixed structure which does not need oiling is pollution free and maintenance free.

Huabao is a pollution free insecticide which has strong contact poisoning function on aphids, cicadas, mites and scales.