考研数3是什么

秦朝的“三公”是指（ ）

A.司马、司徒、司空
B.丞相、太尉、御史大夫
C.丞相、大司马、大司空
D.太师、太傅、太保

Text 4 To combat the trap of putting a premium on being busy,Cal Newport,author of Deep work:Rules for Focused Success in a Distracted World,recommends building a habit of“deep work”—the ability to focus without distraction.There are a number of approaches to mastering the art of deep work—be it lengthy retreats dedicated to a specific task;developing a daily ritual;or taking a“journalistic”approach to seizing moments of deep work when you can throughout the day.Whichever approach,the key is to determine your length of focus time and stick to it.Newport also recommends“deep scheduling”to combat constant interruptions and get more done in less time.“At any given point,I should have deep work scheduled for roughly the next month.Once on the calendar I protect this time like I would a doctor’s appointment or important meeting”,he writes.Another approach to getting more done in less time is to rethink how you prioritize your day—in particular how we craft our to-do lists.Tim Harford,author of Messy:The Power of Disorder to Transform Our Lives,points to a study in the early 1980s that divided undergraduates into two groups:some were advised to set out monthly goals and study activities;others were told to plan activities and goals in much more detail,day by day.While the researchers assumed that the well-structured daily plans would be most effective when it came to the execution of tasks,they were wrong:the detailed daily plans demotivated students.Harford argues that inevitable distractions often render the daily to-do list ineffective,while leaving room for improvisation in such a list can reap the best results.In order to make the most of our focus and energy.we also need to embrace downtime,or as Newport suggests,“be lazy.”“Idleness is not just a vacation,an indulgence or a vice;it is as indispensable to be brain as Vitamin D is to the body...[idleness]is,paradoxically,necessary to getting any work done,”he argues.Srini Pillay,an assistant professor of psychiatry at Harvard Medical School,believes this counter-intuitive link between downtime and productivity may be due to the way our brains operate When our brains switch between being focused and unfocused on a task,they tend to be more efficient.“What people don’t realise is that in order to complete these tasks they need to use both the focus and unfocus circuits in their brain”.says Pillay.
The study in the early 1980s cited by Harford shows that________.

A.distractions may actually increase efficiency
B.daily schedules are indispensable to studying
C.students are hardly motivated by monthly goals
D.detailed plans many not be as fruitful as expected

女性，30岁。贫血、黄疸伴关节疼痛3个月。查体：中度贫血貌，巩膜轻度黄染，脾肋下3cm，实验室检查：血红蛋白60g/L，白细胞9X109/L，血小板120X109/L，网织红细胞计数0.25，外周血涂片提示成熟红细胞大小不等，可见到少量球形红细胞和有核红细胞，骨髓增生活跃，以红系增生为主。无家族史。
该患者诊断最可能是

A.遗传性球形红细胞增多症
B.葡萄糖-6-磷酸脱氢酶缺乏症
C.自身免疫性溶血性贫血
D.阵发性睡眠性血红蛋白尿