oxygen hydrogen torch

例句：

1. 1. Oxygen is essentialfor life on Earth.
   氧气对地球上的生命至关重要。
2. 2. The lungs need oxygen to carryout their functions.
   肺部需要氧气来执行其功能。
3. 3. The scientist studied the effects ofoxygen on the human body.
   这位科学家研究了氧气对人类身体的影响。
4. 1.Hydrogen is a common element inmany compounds.
   氢是许多化合物的常见元素。
5. 2. The hydrogen molecule contains two protons and one neutron.
   氢分子包含两个质子和一个中子。
6. 3.Hydrogen is used as a fuelin internal combustion engines.
   氢被用作内燃机燃料。
7. 1. The firefighters used a torch to extinguish the flames.
   消防员使用火炬扑灭火焰。
8. 2. The torch lit up thedark night sky.
   火炬照亮了黑暗的夜空。
9. 3. The torch was used to guide theway through the forest.
   火炬被用来在森林中引路。