Fill in the blanks with the appropriate connecting elements of the sentence. Deoxygenation is the most important potential effect ... organic waste discharges. However, toxic compounds such ... ammonia may be present in such wastes, particularly where they have been stored ... some time and have become septic. This can happen ... farm wastes, in which the presence of compounds such as ammonia ... hydrogen sulphide probably contribute as much as the deoxygenating capacity of these wastes to the devastating effect ... fish stocks ... pollution incidents.
on, and, in, for, of, with, as.
