SILICEOUS FOSSIL MEALS (FOR EXAMPLE, KIESELGUHR, TRIPOLITE AND DIATOMITE) AND SIMILAR SILICEOUS EARTHS, WHETHER OR NOT CALCINED, OF AN APPARENT SPECIFIC GRAVITY OF 1 OR LESS.

• 硅质化石粗粉(例如各种硅藻土)及类似的硅质土,不论是否煅烧,其表观比重不超过1