已知曲线y=$\frac{1}{6}$x²﹣1与y=1+x³在x=x₀处的切线互相垂直，求x₀的值．

关于“种子的结构”和“种子的萌发”，回答下列有关问题：

世界极端最低气温出现在（    ）

                                                                                               House of Porridge
    Welcome to Clark's Porridge House. We have different kinds of porridge. We have meat porridge, vegetable porridge. And fruit porridge is our special, it is only RMB 4 yuan for one bowl. A bowl of meat is RMB 5 yuan. Vegetable porridge is RMB 3 yuan for one bowl, but RMB 5 yuan for two. We have thin pancakes, too. They are RMB 5 yuan for ten. Come and taste the delicious food here. If you are too busy to come, make a telephone call to us and we can send the food to you in 20 minutes.
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