Help please?!? Which two countries were affected by the cyanide that flowed into the dunube river?

Cyanide is highly toxic, and is lethal to humans and other species even in very small doses. The cyanide contaminated water has now been carried to the river Danube which flows through Serbia, Bulgaria and Romania

Explanation:

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

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.