${}^{7}\mathrm {Be}$ solar-neutrino flux measured via ${{\mathit \nu}_{{{e}}}}$ elastic scattering. This process is sensitive to all active neutrino flavors, but with reduced sensitivity to ${{\mathit \nu}_{{{\mu}}}}$, ${{\mathit \nu}_{{{\tau}}}}$ due to the cross-section difference, $\sigma\mathrm {({{\mathit \nu}} _{{{\mathit \mu}}, {{\mathit \tau}}} {{\mathit e}})}$ $\sim{}0.2$ $\sigma\mathrm {({{\mathit \nu}_{{{e}}}} {{\mathit e}})}$. If the ${}^{7}\mathrm {Be}$ solar-neutrino flux involves nonelectron flavor active neutrinos, their contribution to the flux is $\sim{}0.2$ times that of ${{\mathit \nu}_{{{e}}}}$.