题干

计算2a﹣a,正确的结果是(   )

A:﹣2a3

B:1

C:2

D:a

上一题 下一题 0.0难度 选择题 更新时间:2019-05-28 03:22:17

答案(点此获取答案解析)

D

同类题1

阅读下面的文字,完成后面问题。
        任何民族的饮食乃至由饮食折射出的文化特质都体现了这个民族独一无二的文化风范。中华文化的核心理念体现在“和”字上,“和”有“中和”“融合”之意。中华饮食的发展鲜明地体现了“和”文化的思想精髓。
        中华饮食起源于农耕文明,大量食物来自土地。随着民族文化的交融,汉族逐渐接受了游牧民族的“肉食”饮食方式,扩大了食物范围,丰富了饮食结构。汉唐以后,中亚及东南亚等地的食物品种大量引进,增补了中华饮食品种。近世以来,西方饮食理念与方式得到认同,具有现代特征的中华饮食形态逐渐形成,翻开中国食谱,到底哪种是地道的中国食物或外来食物,人们恐怕已经模糊。大量外来食物品种能够进入中国并转化为饮食的有机部分,不仅在于地理条件与自然气候为其提供了生长发展的基本环境,更重要的还在于中国人将其放在“和”文化的平台上加以吸纳。
        在外来食物或饮食方式的同化过程中,中华饮食突显出“本土化”的内在机制与运作模式,而本土性是始终坚持的首要原则。中国南方多水田,北方多旱地。米和面成为中国人的主食,水、旱地中生长的瓜果蔬菜成为与主食相伴的食物,家畜、水产品及野猪等动物大多成为改善人们生活的佳肴。尽管这种饮食结构及生活方式在物质极大丰富后发生了巨大变化,但中华饮食最根本的本土性特质却仍以不同形式存在,且构成中华饮食文化体系最为坚实的基础。在世界上任何一个提供“中式餐饮”的餐馆与酒店中,中国本土化饮食要素不可或缺。只有中国本土性的饮食原料与中国厨艺有机结合,人们才能真正品尝到中华美食的滋味。
        中华饮食引进外来食物的过程中,一是接受,二是消融。引进接受是前提,消融改造是目的。经过消融改造的食物同时被赋予新的含义,融入到传统的中华饮食中。如原产非洲的油料作物“芝麻”,在中华饮食长期实践与探索中还被广泛地用为调味品,与本土饮食有机结合,被加入到许多甜馅、糕点、饼类食品中。中华饮食文化历久弥新,还在于不断汲取周边各民族及域外的有益文化元素,进而推动中华饮食文化的变革。如中餐“合餐制”的形成。自先秦两汉至唐代,进食采用“分餐”方式。南北朝时期,胡人用的被称作“胡床”和“貊盘”的器具开始逐步向中原地区流传。“胡床”即现在的马扎,“貊盘”是一种较大的餐桌,它们便于餐者起坐取食。这些饮食器具的大范围推广以及对其进一步的改造创新,打破了跪坐而食的局限,形成了围坐合食的进餐形式。而对“合餐制”的全面接受与文化认同,事实上也建构在“和”文化的理念之上。
        随着生产力的发展和生活水平的提高,饮食的功能必然超越物质层面进入精神范畴,并被赋予新的文化内涵。作为人类饮食文化的一种存在样态,中华饮食文化不仅在物质层面上体现了人对世界和自然的深刻认知与利用,更在精神层面上表达了人对美好事物不懈追求的愿望。在全球化时代,中华饮食文化并不会失去自我,而将在人类普遍的文化价值认同之下进一步为世界各国所认同。

同类题2

任务型阅读

    Changes that will help you get more done than ever before

    Win tomorrow today. All it takes is setting aside five minutes every evening before you end your work to establish the one goal you will accomplish tomorrow. Sometimes, the hardest part of getting things done is deciding which thing to work on first. If this decision making has to happen first thing in the morning, it can create a block to progress, which is no way to start your day. By giving yourself a head start the night before, you're allowing your most productive work hours-in the morning—to be used to the fullest by not having to wonder about on choose what you'll work on first.

    Having a morning routine is one of the best things you've done for yourself. It not only helps you set your day up to be successful by gaining great power first in the morning, but it also allows you to guarantee that you are going to get a set number of things done right away. This way, no matter what your day brings, you should keep in mind that your health and nutrition are the most important. Your morning routine includes a workout, drinking water, meditation(冥想), and ensuring you get the nutrients you need to perform at a high level all day.

    One of the common mistakes people make is to focus entirely on whatever task is next on their list and promise not to move or pause until it's done. Tasks will expand to the time assigned. Instead, try to be inspired from successful people and setting up timed periods for both focused work and breaks. Establishing sections where you have a set amount of focus time followed by a set amount of refresh time prevents you from being distracted(注意力不集中的)and helps you make great progress on the tasks and projects you're working on.

    Being extremely future-focused and ambitious is great, but if you're always moving from one task to another, you could be missing out on a big growth opportunity. In order to learn what's working and what's not working, you need to spend time reflecting. Set aside some time at least every 10 days to reflect on the good, the bad, and everything in between. When you can identify what's working, you'll know what to double down on. You'll also be able to identify the things that are holding you back from getting where you want to go, and to think out solutions for those struggles in order to remove them in the future.

    If you really want to get more done, you have to stop focusing on what you can't do, and start focusing on everything that's going right. Being grateful will not only increase your happiness factor, it will also make you more productive. When you have a positive attitude and take time out to recognize everything you have to be grateful for, you're able to focus on the many things you have accomplished, you're more likely to make progress and get more done.

“ Changes that will help you get more done than ever before

Plan in

____

Set aside five minutes every evening to establish the one goal you will accomplish tomorrow. It will block your progress if you decide what to do first and what to do next the next morning.

It can make your time be____ used by giving yourself a head start the night before.

Adjust your morning

routine

It helps you set your day up for ____ by gaining great power first in the morning.

It also allows you to guarantee that you are going to get a set number of things done right away.

No matter how you arrange your day, the most important thing is your health and ____

____work into

sections

•Take ____ from successful people and set up timed periods for both focused work and breaks.

•Establishing sections helps you____ distractions and make great progress on the tasks and projects you're working on.

Make time for 10-day recaps (重述要点)

•You need to allow ____ time to learn what's working and what's not working.

•Set aside some time at least every 10 days to reflect on things whether they are good or bad.

Be thankful

•____ what you can't do and focus on what you can do.

•Being grateful will make you feel ____ and increase your productivity.