Rat chi tiet, mach lac va cung rat that voi long. K fai ninh dau nha, e viet van rat gioi, cai nay rat thuan loi cho e viet luan van tot nghiep DH sau nay do. Sau chuyen nay a so nhung 4rum khac nhin vao va noi PA mat doan ket, con ong co cai nick lethanhtung ji do nua cung muon noi loan day ( e wa toppic cua NDT se thay. Dang on = dt