Which of the following limits is/are equal to unity?

$\underset{\mathrm{x}\to 0}{lim} \left(\right[1+\left|\mathrm{x}\right|]{)}^{\frac{1}{\left|\mathrm{x}\right|}}$ (where [.] denotes greatest integer function) 

$\underset{\mathrm{x}\to 0^{+}}{lim} \frac{\sqrt{1-{\mathrm{e}}^{-\mathrm{x}}}-\sqrt{1-\cos \mathrm{x}}}{\sqrt{\sin \mathrm{x}}}$

$\underset{\mathrm{x}\to 0^{+}}{lim} \left((\tan \mathrm{x}{)}^{\sin \mathrm{x}}+(\sin \mathrm{x}{)}^{\tan \mathrm{x}}\right)$

$\underset{\mathrm{n}\to \mathrm{\infty }}{lim} \frac{\sum _{\mathrm{k}=1}^{\mathrm{n}+1} {\mathrm{k}}^2}{\sum _{\mathrm{k}=1}^{\mathrm{n}} {\mathrm{k}}^2},\mathrm{n}\in \mathrm{N}$