If a moth detects pheromones, how might it work out which direction they are coming from?

by its air concentration or diffusion

Explanation:

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.

answer; (b) clear with a slight blue tint;