Helium is a very light gas that is colourless and has no smell.
英漢詞典釋義
n.
<化>氦
helium balloons for the children’s party兒童聚會用的氦氣球
英英詞典釋義
Noun
1. a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)