Sentence:  The single-barrel Stevens 940 Y ( under $ 35 ) is made with a side lever rather than a top-tang lever because many youngsters <WSD>are</WSD> n't strong enough to operate a top tang to open a gun - and the side lever does indeed open very easily . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)