时间:2019-01-20 作者:英语课 分类:Scientific American(七)月


英语课

   Lawn enthusiasts 1 love a lush, green carpet of grass, which is why they hate crabgrass. And now they may have one more reason to despise the weed. Because crabgrass isn't just faster-growing than the rest of lawn. It may actually be poisoning the lawn, by pumping herbicide into the soil. That's according to a study in the Journal of Agricultural and Food Chemistry. Researchers grouped crabgrass hydroponically, so they could easily capture any chemicals released by the plant's roots. Then they dripped that hydroponic solution into pots of wheat, corn and soy bean seedlings 2. Two weeks later, they dried and weighted the seedlings. And sure enough, the crabgrass solution had significantly stunted 3 the seedlings' growth, compared to control plants. And since corn is in the same family as lawn grasses, the crabgrass toxic 4 effect may also spill bad news for your beautiful Kentucky bluegrass. The researchers still aren't exactly sure how crabgrass' chemical weapons work. But the weed can wipe out beneficial bacteria and fungi 5 in the soil, too. So it's possible crabgrass poisons its neighbors directly, by releasing toxins 6 and indirectly 7, by creating inhospitable soil. Either way, it's bound to make lawn-owners crabby.



n.热心人,热衷者( enthusiast的名词复数 )
  • A group of enthusiasts have undertaken the reconstruction of a steam locomotive. 一群火车迷已担负起重造蒸汽机车的任务。 来自《简明英汉词典》
  • Now a group of enthusiasts are going to have the plane restored. 一群热心人计划修复这架飞机。 来自新概念英语第二册
n.刚出芽的幼苗( seedling的名词复数 )
  • Ninety-five per cent of the new seedlings have survived. 新栽的树苗95%都已成活。 来自《现代汉英综合大词典》
  • In such wet weather we must prevent the seedlings from rotting. 这样的阴雨天要防止烂秧。 来自《现代汉英综合大词典》
adj.矮小的;发育迟缓的
  • the stunted lives of children deprived of education 未受教育的孩子所过的局限生活
  • But the landed oligarchy had stunted the country's democratic development for generations. 但是好几代以来土地寡头的统治阻碍了这个国家民主的发展。
adj.有毒的,因中毒引起的
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
n.真菌,霉菌
  • Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
  • The lawn was covered with fungi.草地上到处都是蘑菇。
n.毒素( toxin的名词复数 )
  • The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
  • Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》
adv.间接地,不直接了当地
  • I heard the news indirectly.这消息我是间接听来的。
  • They were approached indirectly through an intermediary.通过一位中间人,他们进行了间接接触。
标签: 美国科学60秒
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adiplon
alloparalectotype
Andira araroba
angiopoietins
Audied
balloters
braid
Bridge of Allan
British American Tobacco PLC
buyer's option
buzuq
by mutual consent
cabanne
canales semicircularis superior
carballoy
carpings
chipped off
cigarette tax
citrus leaf-roller
command processing overhead
communis juris
compromittee
concept(ual) model
conepenetrometer
conflict justice
convertible note
cool-bags
critical surfce
crossed foliated structure
crude oil paraffinic
curve milling machine
destructive service
dishevelledly
dissipative factor
distolabiopulpal
druks
dukes of marlborough
dummy-node voltage
electr
filling procedure
finiteness problem
flatbushes
from dominant to recessive
Gell -Mann-Nishijima scheme
genus tungas
granulometric facies
horticultural machinery
how old
hystricidaes
I.Q.
identity disorder
individual file
large-scale photograph
lechayi m
letter and telegram register
Lokuru
lose one's appetite
low mammalian toxicity
maged
main-gauche
mean spacing of local peaks of the profile
Melanesia
menials
message lock mode
mulch tillage
nail fixing
Neptune
Nikopol'
packie
paper-lined structure
path-breakings
paying remuneration according to standard output
Penja
perisaturnium
phenolphthalein acidity
procedural fairness
protection fores ?
put something out of one's mind
puzzle oneself about
RAIB
return on net worth
rough coal
rough machined
Sepracor
share-grass
slant product
spatial experience
splice pad
system storage pool
tail folds.
tailblock
tarte
turned his back on
unrepentable
unshiny
usage statistics
variable argument
visceral sag
web-buildings
wrestles
Xinjiekou
Yaredes