2. Hydrogen gas is odorless and
nontoxic but may induce suffocation by diluting the concentration of oxygen in air below levels necessary to support life.
氢是无嗅无毒的,但通过把空气中氧的浓度稀释到维持生命所必须的水平以下,氢可以引起窒息。
3. The results indicate that the covering and rewriting abilities of the new
nontoxic correction liquid can be compared favourably with those available in the market.
试验结果表明,这种新型无毒涂改液的遮盖力和再书写性能等指标均可与市售的涂改液相媲美。