① H - O - H\qquad\qquad

② H - C \equiv N

③ \begin{array}{c}H \\[-2pt]\vert \\[-2pt]H - C - H \\[-2pt]\vert \\[-2pt]H\end{array}

④ \begin{array}{c}H - N - H \\\hspace{0.0em}| \\\hspace{0.3em}H\end{array}

⑤\ H - C = C - H\\[-4pt]\qquad\ \ \, | \qquad\quad | \\[-4pt]\qquad\ \,H \quad\ \quad H