题目

计算的最值时，我们可以将化成，再将分式分解成，然后利用基本不等式求最值；借此，计算使得对一切实数x都成立的正实数的范围是__▲____ 答案：____new wave of Chinese migration is under way, fuelled by ever-younger students for whom.English is not a piece of knowledge but a living language to unlock ____ door of the wider world.A.The; theB.The; aC.A; theD.A; a