新编英语第三版课文里的一句:The part of my brain that switches off when I do anything strenuous signaled shutdown and my feet moved metronomically.这里的signaled shutdown是什么意思,充当什么成分?
老师,这是从VOA英语里摘抄的一句话,请看:For more than 10
years, suicide rates among students aged 10 and up in the U.S. have been on the
rise. 10多年来,美国10岁及以上学生的自杀率一直在上升。请问这里的up是什么词性?省略了什么成份?谢谢...