mot thua ruong hcn co chieu dai la 2/5 km chieu rong bang 5/8 chieu dai hoi dien tich cua thua rong la bao nhieu m2? tren thua rong do nguoi ta trong lua va khi thu hoach duoc tat ca la 2 tan thoc hoi moi met vuong ruong thu hoach duoc bao nhieu kg thoc