The main inorganic nutrients required in primary productivity ...

[Bob-Dole]

The main inorganic nutrients required in primary productivity include ____________ and ____________. Fill in the blank(s) with the appropriate word(s).

Question 2

The ____________ ____________ is the uppermost layer of seawater lit by the sun, whereas the ____________
  ____________ is the permanently dark layer of seawater. Fill in the blank(s) with the appropriate word(s).

[at]

Answer to Question 1

nitrogen, nitrate, NO3-
phosphorus, phosphate, PO43-

Answer to Question 2

photic zone; aphotic zone
euphotic zone; aphotic zone

[Bob-Dole]

Thanks for the timely response, appreciate it

[Viet Thy]

Gracias!