The children used the playpen during the day to ensure they stayed safe while playing.
孩子们在白天使用游戏围栏，以确保他们在玩耍时保持安全。
A playpen is often used in early childhood education settings to provide a contained play area.
游戏围栏通常在早期儿童教育环境中使用，以提供一个封闭的玩耍区域。