时间:2019-02-23 作者:英语课 分类:英语时差8,16


英语课

 When you have an itch 1, you scratch it. What could be more simple than that?   Scratching itches 2 is one of our most basic instincts, one which we share with many other animals. Have you ever stopped to wonder, mid-scratch, exactly why scratching is so effective against itching 3? We'll learn the itchy truth, on today's Moment of Science.


On the most basic level, scratching is a way to remove whatever irritant might be causing the itch in the first place. If an insect is biting you, or you have a patch of dead, flaking 4 skin, scratching has a good chance of getting rid of it. In this case, it's pretty obvious why the scratching works.
Much of the time we scratch, however, it seems to be somewhat after the fact. Perhaps the mosquito has already bitten us and flown away, and we are left scratching at the swelling 5 bite. Clearly this won't get rid of the mosquito. Is there any good reason for this kind of scratching, or is this just an over-zealous instinct that doesn't realize it's too late?
Actually, this kind of scratching can serve two additional functions. First, it can stimulate 6 the irritated tissues and cause extra blood to flow to them. This can help your immune system remove whatever itchy substances might be below your skin. Second, it can trick your brain into ignoring the annoying itch. Your nervous system can generally process only one stimulus 7 from a given area of your skin at a time. If you scratch at an area that itches, this new, greater stimulus can override 8 the itching, effectively blocking it out. 

n.痒,渴望,疥癣;vi.发痒,渴望
  • Shylock has an itch for money.夏洛克渴望发财。
  • He had an itch on his back.他背部发痒。
n.痒( itch的名词复数 );渴望,热望v.发痒( itch的第三人称单数 )
  • His wool shirt always itches him. 他的羊毛内衣总是使他发痒。 来自《现代汉英综合大词典》
  • This wool shirt itches my back. 这件羊毛衫使我背上发痒。 来自《现代英汉综合大词典》
adj.贪得的,痒的,渴望的v.发痒( itch的现在分词 )
  • The itching was almost more than he could stand. 他痒得几乎忍不住了。 来自《现代汉英综合大词典》
  • My nose is itching. 我的鼻子发痒。 来自《简明英汉词典》
刨成片,压成片; 盘网
  • He received ointment for his flaking skin. 医生给他开了治疗脱皮的软膏。
  • The paint was flaking off the walls. 油漆从墙上剥落下来。
n.肿胀
  • Use ice to reduce the swelling. 用冰敷消肿。
  • There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。
vt.刺激,使兴奋;激励,使…振奋
  • Your encouragement will stimulate me to further efforts.你的鼓励会激发我进一步努力。
  • Success will stimulate the people for fresh efforts.成功能鼓舞人们去作新的努力。
n.刺激,刺激物,促进因素,引起兴奋的事物
  • Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
  • Light is a stimulus to growth in plants.光是促进植物生长的一个因素。
vt.不顾,不理睬,否决;压倒,优先于
  • The welfare of a child should always override the wishes of its parents.孩子的幸福安康应该永远比父母的愿望来得更重要。
  • I'm applying in advance for the authority to override him.我提前申请当局对他进行否决。
学英语单词
age of information
al-hallaj
all weather patrol boat
anastasio somoza
atmospheric diving system
automatic-operated valve
Babits, Mihaly
Balifondo
ball of the foot
beam control apparatus
Bessie Smith
beta point source
black root rot fungus
button drainage
cellophane noodles
chemical glove
Chievitz's layer
climatograph
cocostearin
concertinos
consecutive line
covert-coat
cyclodienes
deep recessed part
disavaunced
Egglkofen
electrochemical double layer
Elsholtzia splendens
epinephelus bontoides
erodibilities
feel betrayed
foundry sand preparation plant
FYR for your reference
gandolfoes
glochidion wilsonii hutch.
Halltorp
hiatoplasty
high capacity shell
Hilgard Deep
illusionable
Insinger
interlining
isothermal region
itavia
jingo
kahler
KIH9201
Languedoc
leading-out terminal
load-carring ability
long-term care
Luf I.
Lux.
magnetic pickup coil
meal offering
microscelous
motion gaming
neddenriep
newer
Nonoava
nuclear radiation resistant bearing
nycotometer
onerous contract
online output
optical whitening
outlie
Pentacel
PERT cost system
pet hate
Planck's theory
poachings
poberal
premastering
pressure reducing reservoir
pressure volume curve
prestressed concrete
primary printer
put your tongue out
pyramid-building
Rabdosia grosseserrata
radel
raster laser plotter
rated section
rhodesiella elegantula
schaik
Schawlow
silk floss
supply column
supraorbital process
symphorol
tablemiunt
Tanamicin
task reassingment
Tegueste
the bloomsbury group
titanium dioxide-coated mica
trapeze harness
Tsadha
undermilled rice
veyllard
wheelers
wouldn't miss it for the world