  For a family of second-order elliptic systems in divergence form with rapidly
oscillating almost-periodic coefficients, we obtain estimates for approximate
correctors in terms of a function that quantifies the almost periodicity of the
coefficients. The results are used to investigate the problem of convergence
rates. We also establish uniform H\"older estimates for the Dirichlet problem
in a bounded $C^{1, \alpha}$ domain.
