| 1. | A fountain of helium spurt out of the tube . 有一股氦的喷泉从小管中喷出。 |
| 2. | Helium is a gas used in balloons . 氦是一种用于气球的气体。 |
| 3. | Helium was discovered on the sun . 氦是在太阳上发现的。 |
| 4. | Hydrogen might be depleted with some of it turning into helium . 氢可能被耗尽,一部分变为氦。 |
| 5. | One safety catch in his design is its helium coolant . 这次设计中采用的一个安全措施就是使用氦冷却剂。 |
| 6. | After hydrogen, the atom with the simplest structure is that of helium . 在氢元素之后,氦的原子结构最简单。 |
| 7. | The deuteron can fuse with another proton to make a helium 3 nucleus . 氘核可以和另一个质子聚合以生成一个氦3核。 |
| 8. | When helium is cooled to very low temperatures, it forms an astonishing liquid . 当氦冷却到很低温度时,它会形成一种奇妙的液体。 |
| 9. | The discovery also explains why helium is found in radioactive mineral deposits . 这个发现也解释了为什么在放射性矿渣中找到了氦。 |
| 10. | There is gradual transition from an optimum level into excessive levels of nitrogen . 从氦素适宜水平进入过量水平的转变是逐渐的。 |