But the levels can fluctuate between normal and abnormal throughout the course of the disease.
Conidia are always present in the air, but levels fluctuate from day to day and with the seasons.
The sound levels and frequency fluctuate throughout making this difficult listening despite a good band performance.
"The level hasn't fluctuated in the last six hours," Pendergast replied.
Without the hormone, the levels of calcium in the plant fluctuate rapidly, and the stomata stay open.
The level fluctuates widely due to irrigation demands and the seasonal rainfall.
Income tax relief will fluctuate as levels of interest fluctuate.
This level has fluctuated somewhat during the 20th century, but remained quite high at all times.
The level of new orders has fluctuated widely in the last few months.
Each commodity commands its own price, the level of which fluctuates with the market's demands and requirements.