" It gives them a chance to reset their concentration , " says coker .
科克说：“这给了他们重新调整注意力的机会。”
U of m professor dr. brent coker also surveyed a small sample of office workers ( 300 to be exact ) and came to a rather different conclusion .
墨大教授布伦特科克博士也对300名上班族进行了小规模抽样，得出的结论大相径庭（link）。
Hydrocracking catalyst for coker diesel cas .
焦化柴油加氢裂化催化剂。
However , coker said the study looked at people who browsed in moderation , or were on the internet for less than 20 percent of their total time in the office .
但科克指出，该研究调查的是适度上网、或上网时间不到总工时20%的人。
" Firms spend millions on software to block their employees from watching videos , using social networking sites or shopping online under the pretence that it costs millions in lost productivity , " said coker . " That 's not always the case . "
