We have gone through many difficulties.

He spends a lot of time studying.

He reads a lot of books.

This problem is very difficult.

In order to overcome these difficulties, we all need to cooperate.

He was able to accurately describe the location of the hyoid bone.

I saw a sea otter at the zoo.

He will never forgive me.

The children were playing tag in the park.

He really is a music child, isn't he?