3 sentences

1. 钙对骨骼健康很重要。

   gài duì gǔ​gé jiàn​kāng hěn zhòng​yào.

   Calcium is important for bone health.

   Source: Dong Chinese Dictionary

2. 牛奶中含有丰富的钙等矿物质。

   niú​nǎi zhōng hán​yǒu fēng​fù de gài děng kuàng​wù​zhì.

   Milk is rich in minerals such as calcium.

   Source: Dong Chinese Dictionary

3. 碳酸钙是构成大理石的主要成分。

   tàn​suān gài shì gòu​chéng dà​lǐ​shí de zhǔ​yào chéng​fèn.

   Calcium carbonate is the main component of marble.

   Source: Dong Chinese Dictionary