儿童龋齿是一个全世界普遍的现象。

Dental decay in children is a common phenomenon all over the world.

youdao

儿童龋齿在全世界都是一个普遍现象。

Dental decay in children is a common phenomenon all over the world.

youdao

儿童龋齿在全世界都是一个普遍现象。

Dental decay in children is a common phenomenon all over the world.

youdao