Fill in the gaps with appropriate prepositions. The vast number (a) — plant species underwater forms a beautiful ecosystem. The plants which stay underwater depend (b) — the light coming (c) — the sun (d) — their growth. They also draw the atmospheric carbon dioxide (e) — the air above and convert them (f) — oxygen. The flora (g) — the surface (h) — the water adds (i) — the aesthetic beauty. These plants sometimes span vast lengths below the surface (j) —the ocean.