\r\n\r\nKho\u1ea3ng th\u1eddi gian t\u1eeb th\u00e1ng 4-8 t\u01b0\u01a1ng \u0111\u1ed1i \u0111\u1eb9p \u0111\u1ec3 \u0111\u1ebfn \u0110\u00e0 N\u1eb5ng ngh\u1ec9 d\u01b0\u1ee1ng v\u00e0 t\u1eafm bi\u1ec3n. V\u1edbi m\u1ed7i kho\u1ea3ng th\u1eddi gian kh\u00e1c nhau, \u0110\u00e0 N\u1eb5ng s\u1ebd c\u00f3 nh\u1eefng n\u00e9t \u0111\u1eb9p ri\u00eang cu\u1ed1n h\u00fat kh\u00e1ch du l\u1ecbch (t\u00f9y theo \u00fd t\u01b0\u1edfng ri\u00eang c\u1ee7a m\u1ed7i ng\u01b0\u1eddi), tuy v\u1eady \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o s\u1ebd c\u00f3 nh\u1eefng tr\u1ea3i nghi\u1ec7m tuy\u1ec7t nh\u1ea5t b\u1ea1n c\u00f3 th\u1ec3 \u0111\u1ecdc th\u00eam m\u1ed9t s\u1ed1 th\u00f4ng tin nh\u01b0 sau:\r\n