Deep inelastic cross-section measurements at largeywith the ZEUS detector at HERA

The reduced cross sections for $e^{+}p$ deep inelastic scattering have been measured with the ZEUS detector at HERA at three different center-of-mass energies, 318, 251 and 225 GeV. The cross sections, measured double differentially in Bjorken $x$ and the virtuality, $Q^2$, were obtained in the region $0.13\le y\le 0.75$, where $y$ denotes the inelasticity and $5\le Q^2\le 110{\mathrm{GeV}}^2$. The proton structure functions $F_2$ and $F_L$ were extracted from the measured cross sections.