若函数
在x=0处连续，则（）
具有土地入股和统一经营特点的是 ___________。
For the new country to survive, ________ for its people to enjoy prosperity, new economic policies will be required.
当x→0时，与根号x等价的无穷小量是（）
The address book ________ the email addresses of your friends or groups of colleagues.
请验证。
