Ifeel a bite and then see the dog that bit me. this is an example of a conditioning procedure which is to be effective.

backward; likely

Explanation:

In backward conditioning, we are exposed to the unconditioned stimulus  before we are aware of the  neutral stimulus. (in the example above, the bite is the unconditioned stimulus, and the dog is the neutral stimulus)

This type of conditioning is only 'Likely' to be effective because the person tend to do not see directly how the neutral stimulus cause the unconditioned stimulus.

Let's examine the example above again :

I feel a bite and then see the dog that bit me.

We can say that the person DO NOT directly witnessed the dog bited him/her. That person only guess that the dog is the one bited him/her since it's close. There is still a chance that the person's bitten by other animals.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals