It's difficult to understand his explanation.

The inner layers of the Earth are extremely hot, and their condition is not yet fully understood.

It's high temperature today, it's hard to go out.

It's difficult to understand his explanation.

My homework is not finished yet.

My homework is still unfinished.

He was helping the villagers as a wizard.

I haven't done my homework yet.

I was amazed at his extraordinary talent.

Please press this button in case of emergency.