When in doubt, throw it out. The smell is the protein breaking down and rotting. With hamburger, if the core is still red and doesn't smell you can use that, but be careful not to mix any from the outside that smells in with what you want to eat. if you have a dog, cook the meet and feed it to them. Their systems are designed to handle things that may bother us. If it's very bad awful smelling, just throw it out completely.
If your question is do they, the answer is yes. All flowers are good for bees.
Comfrey, if that is what you mean, is a herb Symphytum of which there are a number of species. It is supposed to have the power to heal wounds and the leaves make a good if foul smelling liquid fertiliser.
How you can tell if raw beef is still good to cook will be by its' smell and appearance. If it has a use by date, this is also a good indication of whether or not it is good to cook.
There are good and bad bacteria in the sap of trees from the forest floor. The bad bacteria in sap will cause the tree sap to be foul smelling, or dry sap will appear grey.
A platypus's faeces are black in colour, and semi-solid. Most platypuses deposit their faeces in water, so they are unlikely to be seen - which is a good thing, as they are apparently very foul smelling.
do boa snakes have go smelling
just spray it with some thing good smelling a there you hove a good smelling sponge
in smelling.
Good old beef
yes it is very good
More kisses!
The odor is a dead give-away. If it is smelling particularly fishy or of ammonia, it is going-going-gone.