Sentence:  `` When the roles of husband and wife are reversed , so that the wife becomes leader and the husband follower '' , Dr. Linden says , `` the effects on their whole relationship , sexual and otherwise , can <WSD>be</WSD> disastrous '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)