DAY 4
1.state:to express something in speech or writing,especially in a definite or formal way.
Eg:The candidates stated their case at a series of meetings.
2.explicit:said or explained in an extremely clear way,so that you cannot doubt what is meant
Eg:explicit instructions/directions
3.elliptical:1.suggesting what you mean rather than saying or writing it clearly
2.shaped like an ellipse
Eg:He draw an elliptical ball in paper.
4.At rest:not moving
Eg:The earth is not at rest.
5.Non-existent
Eg:a non-existent problem.
6.accord with:to agree with or be the same as something else
Eg:Hemming’s account does not accord with the police evidence.
7.imply:if one thing implies another thing, the other thing is likely to exist or be true.
Eg:The presence of stairs in the ruins implies an upper floor.
8.stub:to hit your toe against something accidentally in a hard and painful way
Eg:His toe was stubbed on a stone
9.interval:a period of time between two events
Eg:The normal interval between our meetings is six weeks.
10.comparative:judged in comparison to something such a previous situation or state
Eg:We sailed into the comparative shelter of the harbour.
11.propagate:to spread an idea,a belief or a piece of information among many people
Eg:Television advertising propagates a false image of the ideal family.
12.ether:the air or atmosphere,especially when you are talking about it as the substance that radio,telephone,or Internet communication pass through
Eg:messages floating around in the ether
13.postulate:an idea that is an important part of a theory,argument,or explanation
14.Mass:the quantity of material that sth contains
Eg:calculating the mass of a planet.
15.intrinsic:relating to the essential qualities or features of something or someone
Eg:Providing good service is intrinsic to successful business.
16.cesium=caesium:a chemical element.Caesium is a soft silver-white metal that reacts strongly in water,used in photoelectric cells.
17.Platinum:a silver-grey metal used in industry and for making expensive jewellery
18.Travel:if light or sound travels from one place to another,it moves there
Eg:Sound travels more slowly than light.
19.coordinate:either of ten numbers or letters used to fix the position of a point on a map or graph
Eg:the x,y coordinates of any point on a line
20.specify:to explain something in an exact and detailed way
Eg:To make a claim,you must specify the date when the article was lost.
DAY 6
DAY 7
这篇文章作者采用了按照历史发展顺序，即正常叙述的思维，从古希腊的亚里士多德的朴素力学观点，到伽利略通过实验来对亚里士多德的理论进行证伪，再到牛顿经典力学及其第一定律和第二定律的产生，最终到爱因斯坦的相对论的提出，让人对时空的观念从三维进入到四维。
当人们提到时空方面的时候，总是会引申出各种各样的话题：黑洞、虫洞、时空穿梭等等，而其中时空穿梭这一话题成为各大影视剧和科幻小说的经典素材，比如《回到未来》系列电影，动漫中的《哆啦A梦》都有涉及到时空穿梭这一主题。