Questions in fun-lim

Select	Question
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{1-\cos 6x}{x}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{\sin mx}{\tan nx}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{3\sin x-\sin 3x}{{{x}^{3}}}=$
	$\underset{x\to 0}{\mathop{\text{lim}}}\,\frac{{{x}^{3}}}{\sin {{x}^{2}}}=$
	If $f(x) = \begin{cases} x,\;\;\;\,\,{\rm{when}}\;x > 1\\ {x^2},\,\,\,{\rm{when}}\,\,x < 1 \end{cases}$, then $\underset{x\to 1}{\mathop{\lim }}\,f(x)=$
	$\underset{x\to \pi /2}{\mathop{\lim }}\,\frac{\tan 3x}{x}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{\sqrt{3+x}-\sqrt{3-x}}{x}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{{{e}^{{{x}^{2}}}}-\cos x}{{{x}^{2}}}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{\log (a+x)-\log a}{x}+k\underset{x\to e}{\mathop{\lim }}\,\frac{\log x-1}{x-e}=1,$ then
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{\sqrt{\frac{1}{2}(1-\cos 2x)}}{x}=$