This car is our family's joint possession.

We are sharing ownership of this project.

His belief is firm.

His belief was firm, and no one could shake it.

Kyoko is my best friend.

An earthquake occurred, and the strong shaking shook the entire house.

We are participating in local mutual aid activities.

We will co-sponsor this event with the city.

I think these teaching materials will be very useful for the students.

Humans and nature should coexist.