(Ⅰ)若a=2,求f(x)在x=1处的切线方程;
(Ⅱ)若f(x)≥0对x∈(﹣1,+∞)恒成立,求实数a的取值范围.
H+____; OH﹣____; CO32﹣____; Cl﹣____; SO42﹣____;NH4+____.
一只小鸟从枇杷树上飞到地面,啄食掉落在地上的熟枇杷,吃了一会儿,路边传来吆喝声,小鸟立即飞回树上它出发时的位置,如图所示,能够大致描述小鸟运动情况的是( )
The fire started on the second floor and it wasn't long ______ the whole building was burned down.
我国四个直辖市中位于长江上游的是( )