题干

Mr Zhang is ___actor .

A:a

B:an

C:the

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答案(点此获取答案解析)

B

同类题1

阅读下面短文,并回答问题.

电磁波在生活中的应用

1947年,第一台微波炉问世,微波炉就是用微波来煮饭烧菜的.微波很有“个性”,一碰到金属就发生反射,金属根本没有办法吸收或传导它;但微波可以穿过玻璃陶瓷、塑料等绝缘材料,且不会消耗能量;而含有水分的食物,微波不仅能透过,其能量也会被吸收.微波炉正是利用微波的这些特性制作的.微波炉的外壳用不锈钢等金属材料制成可以阻挡微波从炉内逃出,以免影响人们的身体健康,装食物的容器则用绝缘材料制成,微波能透食物,并使食物中的水分子也随之运动,剧烈的运动产生了大量的热能,于是食物“煮”熟了.这就是微波炉加热的原理

2009年4月29日,国家重大科技基础设施建设项目﹣﹣上海同步辐射光源竣工.

同步辐射光源具有波长范围宽、亮度高等一系列优异的特性,被科学家称为“为人类文明带来革命性推动的新光源”.

光的波长决定了它与物质的相互作用类型,如“可见光”照射人体时,会反射到我们的眼睛,被视神经所感觉而“看到”人体;而X射线光照射人体时,则会穿透人体,并在X光底片上留下穿透程度的影像记录.

光波具有衍射现象,用光探测物体时,光的波长应当与物体的大小相近或更短.如要“看清”金属原子等微观物体,必须选用与这些微观物体大小相近或更短的波长的光束.科学家利用光束在物质中的衍射、折射等特性来探究未知的微观世界.

(1)在微波炉中应选用下列哪种容器来加热饭菜____ 

A.不锈钢盆子   B.铁盆子   C.玻璃盆子   D.铜制盆子

(2)微波在真空中传播速度是____ m/s,微波____ 能量(选填“具有”或“不具有).

(3)为安全使用微波炉应选用____ 孔插座,微波炉的外壳可以用 不锈钢 材料制成(选填“塑料”、“不锈钢”或“陶瓷”).

(4)红外线的波长比紫外线的波长____ ,某种红外线的波长为6.0×10﹣5m,它的频率为____ Hz.

(5)用放大倍率很高的普通光学显微镜也看不见原子等微观物体,其原因是____ .

同类题3

阅读理解

    On a recent visit to the Museum of Modem Art with a friend and her daughter, wandering through the museum's exhibits, I was struck by how often my friend's 13-year-old daughter asked us to take photos of her with her smart phone in front of the artwork. Then, she gazed at the photos which she would then post on Instagram, Snapchat and all the rest. She was not the only person who was doing this; it seemed everyone was busy taking photos of themselves "experiencing" the museum.

    This is by no means a criticism of my friend's daughter or anyone else. What was concerning, at least to me, was that in between being photographed and posting, my friend's daughter had no interest in the artwork, a fact which didn't seem to matter or have anything to do with wanting to post herself as someone enjoying the experience.

    When I was her age, I had no interest in going to museums either. Having no interest in art at her age (and any age) is completely normal. But what is disturbing is how much of a young person's energy these days goes into creating an image of the life they're living and the character they "are" in that life. While creating a self-image has always been a big part of growing up and figuring out our identity, social media seems to have changed the rules of the game. Social media has not just increased the pressure and possibility of creating a self-generated(自我创造的) self-image, but also distorted(歪曲) the process through which we become who we are. Young people now seem to be creating an image of who they are in place of becoming who they are, posting their life rather than living it.

    Social media has turned life and its experiences into an exercise in narcissism(自恋,自我陶醉). No matter what the experience is actually about, it becomes about you, the person who is living it. A concert is not about the music, a restaurant not about the food and a sport event not about the sport; it's all about you, the doer, and what the event says about you. As a result the more we use life create an identity, the more distant from life we feel. Instead of being part of it, we feel as if we have to keep generating new life material.

    I hope the next time you post your story, pause for a moment and experience where you are, feel what it feels like to live what you're living without using life for your benefit, or for anything at all. Just live, without the narrative(叙述). While you may feel this practice is a threat to your identity, causing you to miss a chance to prove your value, in fact, the benefit will far outweigh any loss it brings.