Air whether in the gaseous or liquid state is a fluid.

空气, 无论是气或是液, 都是一种流体。

Water vapor is water in the form of a gas.

蒸气是气。

The results indicated that the trace elements molybdenum and zirconium increased considerably the gas yields of the lignitic organic matter while selenium did not.

分析结果表明,除硒元外,随着钼元和锆元加入,褐煤有机质气产成量显著提高。