Cần đáp án và công thức ở câu đấy. Men and women are often considered to be completely at odds with each other, in terms of their attitudes and behaviour. Not so when they are in love, new research has discovered. As (46) ________ as their hormone levels are concerned when men and women are in love, they are more similar to each other (47)________ at any other time. It has (48) ________ been known that love can (49) ________ havoc with hormone levels. For example, the hormone cortisol, which is known for its calming effect on the body, dips dramatically when one person is attracted to (50) ________, putting the love-struck on a par with sufferers of obsessive compulsive disorder. But a new study has found that the hormone testosterone, commonly associated with male aggression, also falls when he is in love. In women, it's quite the reverse. Testosterone levels, (51) ________ tend to be lower among females, rise towards (52) ________ of the male. Donatella Marazziti of the University of Pisa, Italy, (53) ________ this down to nature attempting to eliminate the differences between the sexes. By doing so, they can concentrate fully (54) ________ reproduction. This suggestion seems to be supported by the fact that neither couples in a long term relationship (55) ________ participants in the study who were single at the time of the experiment exhibited such changes.