Complete the text with the or no article(-).
Baikal
1)- lake Baïkal is in 2) Siberia. Like 3) lake Tanganyika it was formed in an ancient rift valley. It is 4) oldest and 5) deepest lake in the world. The lake is completely surrounded by mountains and on 6) north shore are 7)___ Baïkal Mountains. It is fed by 300 rivers. The main ones are 8)___Selenga river and 9)___ Chikoy river. It is drained through the Angara river into 10) __ Yenissei and at last 11) the Arctic Ocean.