单选题
. ①Benjamin Franklin is portrayed in American history as the quintessential self-made man. ②In "Self-reliance," Emerson asks, "Where is the master who could have instructed Franklin...?" ③In fact, Franklin took instruction widely, and his scientific work was highly collaborative. ④Friends in England sent equipment needed for his electrical experiments, others, in Philadelphia, helped him set up his workshop there. ⑤Philip Syng constructed a device for generating electrical charges, while Tomas Hopkinson demonstrated the potential of pointed conductors. ⑥Franklin, in addition to being the group's theoretician, wrote and published its results. ⑦
His fame as an individual researcher is partly a consequence of the shorthand by which when one person writes about a group's discoveries, history sometimes grants singular credit for collective effort.45. Which of the following best describes the function of the highlighted sentence? ______