`B=\frac{2}{\sqrt{5}-\sqrt{3}}+\sqrt{6-2\sqrt{5}}+\frac{\sqrt{15}-\sqrt{12}}{\sqrt{5}-2}`
`=\frac{2(\sqrt{5}+\sqrt{3})}{5-3}+\sqrt{(\sqrt{5}-1)^2}+\frac{\sqrt{3}(\sqrt{5}-2)}{\sqrt{5}-2}`
`=\sqrt{5}+\sqrt{3}+|\sqrt{5}-1|+3`
`=\sqrt{5}+\sqrt{3}+\sqrt{5}-1+\sqrt{3}`
`=-1+2\sqrt{3}+2\sqrt{5}`