Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases! Level 4 is stable! The whole English grammar system plus level 4 high-frequency phrases!