《战国策·齐二·秦攻赵长平》
而且赵对于燕、齐两国来说，正是御秦的天然屏障。
且赵之于燕、齐，隐蔽也，齿之有唇也，唇亡则齿寒。
Moreover, Zhao is the natural defensive barrier for Yan and Qi against Qin.
<s>[INST] Explain the meaning of this Classical Chinese passage in English: 且赵之于燕、齐，隐蔽也，齿之有唇也，唇亡则齿寒。 [/INST] Moreover, Zhao is the natural defensive barrier for Yan and Qi against Qin.</s>
Explain the meaning of this Classical Chinese passage in English: 且赵之于燕、齐，隐蔽也，齿之有唇也，唇亡则齿寒。
user
Moreover, Zhao is the natural defensive barrier for Yan and Qi against Qin.
assistant