He is spending a lot of time on experimental research.

That plan is too impractical, it's difficult to implement.

I'm troubled by his unproductive attitude.

He was affected by secondary effects.

My hand got caught in the door, and it hurt.

The center of this plate is sunken.

Mr. Zhai is my best friend.

He has a weary character.

Jammu and Kashmir is a beautiful region in India.

He is collecting centime, the old currency of France.