关于一道Argue

sammo3182UID: 2262916

请问一下通用顺序90号题里那个“For a fee”一句是啥意思啊？需要拿出来驳吗？另外，这题貌似比较怪异的样子，觉得很不好develop啊，哪位写过能给个思路不？
附上题目：
The following appeared in an editorial on health problems in the country of Corpora. “Some pharmacies now feature ultrasound machines that screen for an elevated risk of stroke. For a fee, a technician presses a probe against the neck to determine whether any plaque has thickened the walls of the main artery leading to the brain. Researchers have shown that a thickening of artery walls is associated with elevated stroke risk, and such scans typically find that anywhere from 5 to 20 percent of clients have detectable plaque. All pharmacies should offer this service, because early detection of increased risk for stroke will encourage clients to consult with their doctors and make important life-style changes to reduce their risk of having a stroke. This in turn will cause a decrease in overall medical costs in Corpora."