Calcium is a soft white element which is found in bones and teeth, and also in limestone, chalk, and marble.
英漢詞典釋義
n.
〈化〉鈣
We need calcium to make bones.我們需要鈣來壯骨。
英英詞典釋義
Noun
1. a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals