The associative law is one of the basic laws of mathematics.

His talent is something extremely uncommon.

Metallic bonds are formed by ions floating in a sea of electrons.

A metallic bond refers to a strong bond between metal atoms.

It takes twenty minutes to get to my house.

He had twenty old coins.

I started a new job two months ago.

In Japanese, the second person can be expressed as 'anata', 'kimi', 'omae', etc.

My friend can play the erhu well.

He swore never to repeat that mistake twice.