  We have used 4752 days of data collected by the Birmingham Solar-Oscillations
Network (BiSON) to determine very precise oscillation frequencies of acoustic
low-degree modes that probe the solar core. We compare the fine (small
frequency) spacings and frequency separation ratios formed from these data with
those of different solar models. We find that models constructed with low
metallicity are incompatible with the observations. The results provide strong
support for lowering the theoretical uncertainties on the neutrino fluxes.
These uncertainties had recently been raised due to the controversy over the
solar abundances.
