But why water and not, say, hydrogenperoxide or even ammonia?
可是，为什么是水，而不是双氧水或是氨水呢？
2
The system runs on a green hydrogenperoxide propellant that leaves behind only water and oxygen, a solution not too far from the hydrogenperoxide in the common medicine cabinet.
系统使用只会产生水和氧气的过氧化氢环保推进剂，类似家庭常备医药箱里的过氧化氢溶液。
3
Hydrogenperoxide powers the arm for 18 hours of normal activity.