______ occur when the rate of oxygen transfer from the lagoon surface is less than the rate of oxygen consumption in the lower levels of the lagoon.

______ occur when the rate of oxygen transfer from the lagoon surface

1.	______ occur when the rate of oxygen transfer from the lagoon surface is less than the rate of oxygen consumption in the lower levels of the lagoon.
A.	Temperature rise
B.	Objectionable odour
C.	Raised pH
D.	Temperature fall
Answer» C. Raised pH