本集内容. Dogs were man's best friend far earlier than thought. 狗成为人类 “最佳伙伴” 的时间远早于早前认知. 文字稿. It's a small piece of jawbone, bu ...

Ovarian cancer drug, fish skin to treat burns 治疗卵巢癌的新药物测试、罗非鱼皮被用于治疗烧伤 Episode 170608 / 08 Jun 2017 Learn English words and ...