A、Yes. B、No. C、It depends. D、Maybe. A短文中开头提到站着上课有助于学生更有效率地思考吗?德州农机大学的一项新研究表明确实如此。故选A。

Do students think best when on their feet? (19) A new study by the Texas A&M University indicates they do. Ranjana Mehta, Ph. D., assistant professor at the Texas A&M School of Public Health, researched freshman high school students with who used standing desks. (20) Testing was performed at the beginning and again at the end of their freshman year.
    "Test results indicated that continued use of standing desks was associated with significant improvements in executive function and working memory capabilities," Mehta said. "Changes in corresponding brain activation patterns were also observed."
    "Interestingly, our research showed the use of standing desks improved neurocognitive function, which is consistent with results from previous studies on school-based exercise programs," Mehta said. "The next step would be to directly compare the neurocognitive benefits of standing desks to school-based exercise programs."
    "There has been lots of anecdotal evidence from teachers that students focused and behaved better while using standing desks," added Mark Benden, Ph. D., CPE, co-researcher and director of the Texas A&M Ergonomics Center.
    (21) Continued investigation of this research may have strong implications for policy makers, public health professionals and school administrators to consider simple and sustainable environmental changes in classrooms that can effectively increase energy expenditure and physical activity as well as enhance cognitive development and education outcomes.
19. According to the research, do students think best when on their feet?
20. When was the testing performed?
21. Who will be NOT influenced by the investigation?