| 21. | The parietal cells concentrate hydrogen ions more than one million times. |
| 壁细胞浓缩氢离子100万倍以上。
|
| 22. | Hydrogen balloons rise quicker than air filled balloons. |
| 氢气球比空气气球上升得快．。
|
| 23. | Chemical analysis of water yields hydrogen and oxygen. |
| 水经过化学分解会产生氢和氧。
|
| 24. | Water can be reduced to oxygen and hydrogen by electrolysis. |
| 用电解法可以把水分解为氧和氢。
|
| 25. | free hydrogen |
| 游离氢
|
| 26. | a hydrogen [an H] bomb |
| 氢弹
|
| 27. | dissolve water into hydrogen and oxygen |
| 将水分解成氢和氧
|