primitive D-cube of failure

例句：

1. 1.The primitive man lived in caves.
   原始人生活在洞穴里。
2. 2. Primitive tools were made from stone and wood.
   原始工具是用石头和木头制作的。
3. 3. The primitive society was based on hunting and gathering.
   原始社会基于狩猎和采集。