Copper (am, is, are, am not, isn't, aren't) cheap. Diamonds (am, is, are, am not, isn't,...

Question

Copper (am, is, are, am not, isn't, aren't) cheap. Diamonds (am, is, are, am not, isn't, aren't) expensive.

Answer 1

Copper is cheap
diamonds are expensive

Answer 2

Copper is cheap. Diamonds  are expensive.