n.<化>氦;
例句:
Helium and neon are inert gases.
氦和氖为惰性气体.
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.
Unlike helium-4, it cannot be produced by radioactive decay.
与氦 - 4不同之处是, 氦-3不能由放射性衰变产生.