OE


In this sentence we are looking for a word that will contradict the idea that radiation is out of the ordinary - perhaps common or something similar. Ineffable (incapable of being expressed) has to do with whether or not something can be described, which is not in question here - eliminate it. Nebulous means hazy or indistinct. It is not a very good choice, unless perhaps you imagine that it is hard to avoid indistinct things. In any case, it has nothing to do with being out of the ordinary, so you should be able to eliminate it. You can rule out quiescent for similar reasons; it might be hard to avoid something dormant simply because you don't know that it is there, but what would this mean in the context of radiation, and what does it have to do with being uncommon? If you can't answer these questions, you should eliminate the word. Foolproof means never-failing and is more commonly used to describe plans or ideas - eliminate it. The correct answer is ubiquitous, which means present everywhere.