He checked whether he remembered or not.

He took out a book from the bookshelf at the back of the room.

Cyclooctane plays an important role in organic chemistry.

In the ecosystem of this area, 'inquilinism', where certain species parasitize the nests of other species, is common.

Learning about the history of Seiban is important for understanding our past.

Gender discrimination is one of the social issues that needs to be resolved.

Xikang is a historical region name in China.

Finding an asterism is a great joy for astronomers.

The life in the bay is quiet and peaceful.

The Stars and Stripes is the national flag of America.