川の流れの観察技術　To observe the flow of the river

(4:10)

川の流れの観察技術　To observe the flow of the river

(12)

川の流れの観察技術　To observe the flow of the river

(13)

川の流れの観察技術　To observe the flow of the river

(18)

川の流れの観察技術　To observe the flow of the river

(11)

川の流れの観察技術　To observe the flow of the river

(11)

川の流れの観察技術　To observe the flow of the river

(16)

川の流れの観察技術　To observe the flow of the river

(19)

川の流れの観察技術　To observe the flow of the river

(14)

川の流れの観察技術　To observe the flow of the river

(30)

川の流れの観察技術　To observe the flow of the river

(4:22)

川の流れの観察技術　To observe the flow of the river

(20)

川の流れの観察技術　To observe the flow of the river

(22)

川の流れの観察技術　To observe the flow of the river

(17)

川の流れの観察技術　To observe the flow of the river

(17)

川の流れの観察技術　To observe the flow of the river

(11)

川の流れの観察技術　To observe the flow of the river

(15)

川の流れの観察技術　To observe the flow of the river

(30)

川の流れの観察技術　To observe the flow of the river

(14)

川の流れの観察技術　To observe the flow of the river

(16)