已知函数f（x）=e^x﹣ax﹣a（其中a∈R，e是自然对数的底数，e=2.71828…）．

（Ⅰ）当a=e时，求函数f（x）的极值；

（Ⅱ）若f（x）≥0恒成立，求实数a的取值范围．

This green bag is ____(轻的）.

黑色的兔毛和红色的番茄都属于（    ）

There is a new park near Andy's home. It's fine today. Andy and his family are in the park now. On their left, there is a café. On the right, there is a big lake. There are many flowers and trees around the lake. There's a small hill behind the lake. Near the lake, there are two signs（标记）. One says, "Don't swim in the lake."But you can go boating on the lake. There is a beautiful garden in the middle of the park. There are green grass and beautiful flowers in it. There are some small shops between the lake and garden. The park is so nice. Andy and his family like it very much.