$$\mathrm{first\ line} \\ \mathrm{second\ line} \\ \mathrm{third\ line}$$ $$\mathscr{first\ line} \\ \mathscr{second\ line} \\ \mathscr{third\ line}$$ $$\mathfrak{first\ line} \\ \mathfrak{second\ line} \\ \mathfrak{third\ line}$$ $$\mathcal{first\ line} \\ \mathcal{second\ line} \\ \mathcal{third\ line}$$