音标:[ˈekəʊˌsɪstəmz] ;
n. <生>生态系统( ecosystem的复数形式 )
n. a system formed by the interaction of a community of organisms with their physical environment

Broadcast: Jan 16, 2003 Experts say one of the world's most feared, but misunderstood, creatures is under 2) assault by fishermen. A new study of all types of sharks finds that there are fewer of them

发表于:2018-12-08 / 阅读(507) / 评论(0) 分类 VOA2003(上)-科技先知

Report: Ecosystems More Stressed Than Ever When Super Storm Sandy ravaged the U.S. East Coast and inundated New York City in late October, many wondered if such extreme weather events might be linked to climate change, the gradual warming of the plan

发表于:2018-12-08 / 阅读(560) / 评论(0) 分类 VOA标准英语2012年(十二月)

Last week, tens of thousands of gallons of sewage gushed into urban streams in Baltimore, because of leaky pipes and flooding rains. And when that happens, it's not just organic matter and microbes that get flushed into aquatic habitats. It's drug re

发表于:2018-12-24 / 阅读(415) / 评论(0) 分类 2016年Scientific American(八)月

From NPR News in Washington, I'm Lakshmi Singh. A radical Sunni Muslim cleric born in the US is urging religious scholars to promote holy war against American and Israeli interests in the Middle East. NPR's Soraya Sarhaddi Nelson is in Cairo and repo

发表于:2019-01-08 / 阅读(469) / 评论(0) 分类 2010年NPR美国国家公共电台11月

Lonely bug NB: This is not an accurate word-for-word transcript Dima:Hello and welcome to this edition of 6 Minute English with me, Dima Kostenko Rebecca: and me, Rebecca Byrne. Dima:Today we'll have some useful words and phrases used in science and

发表于:2019-01-10 / 阅读(644) / 评论(0) 分类 六分钟英语

Severe Drought, Wildfires Threaten Water Resources This is Valles Caldera. Actually, it's the giant mouth of a dormant super volcano that last erupted 40,000 years ago. In the millennia since then, the terrain developed high-elevation forests, of abu

发表于:2019-01-13 / 阅读(580) / 评论(0) 分类 VOA标准英语2012年(一月)

AGRICULTURE REPORT - Study Warns of Risk to Seafood Supplies in World's OceansBy Jerilyn Watson Broadcast: Tuesday, November 14, 2006 This is the VOA Special English Agriculture Report. A study has wa

发表于:2019-01-30 / 阅读(428) / 评论(0) 分类 2006年慢速英语(十一)月

Topic: In some countries, parents expect children to spend long time studying both in and after school, and have less free time. Task: (You may spend 40 minutes on this task, and write a minimum of 250 words) Do you think it has the positive or negat

发表于:2019-02-09 / 阅读(530) / 评论(0) 分类 雅思英语

SECTION 1 Time - 30 minutes 38 Questions Directions: Each sentence below has one or two blanks, each blank indicating that something has been omitted. Beneath the sentence are five lettered words or s

发表于:2019-02-13 / 阅读(501) / 评论(0) 分类 实用英语

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发表于:2019-02-20 / 阅读(555) / 评论(0) 分类 加州语文教材California Treasures G3
学英语单词
a-c relay
ACOC
advisory council
agonoxenid
agrofuels
Aminoblastin
amoys
ampullar abortions
andeanist
atrium
backupable
bad luck (on someone)
beat sb hollow
Bisporella
bitt standard
bulb bold bow
bumboy
Bunker Grp.
canis dirus
Canscora melastomacea
cassican
centralized planning control
cheaps out
cosmic expansion
crawl out of the woodwork
credit for child and dependent care expenses
cythoclol
decimla
dendronotid
dilston
dipharsine
disolvated
draw-a-person test
electrolytic aluminum
enterprise geography
gather together
gold fix
gross product rate
heterogeneic
hexagonal pyramid of the third order
history of physical education
holocrystalline-porphyritic
homoioteleuton
invert masonry block
isometric map
kribs
Kvanndalsvatn
library adult education
luminaire efficiency
magnesium-iron mica
mana points
manufactured inventories
mascola
material witness
Mazombe
mentorees
morning news
morphochoresis
non-polarized return-to-zero recording
odilon
oleum aurantii
one-subject
pearlite nose temperature
Penrose drain
periostotom
peroplasia
phasianus colchicuss
philopena
pilophorus aciculare
posa
potassium hydrogen disilicate
Pseudomonas synxantha
purulent myositis
quasideterminants
rainier
rope clip
route key
run rider
Sampa
sconsole
seed tuber
serafims
Seybaplaya
shifting charge
shuttle data processing complex
space lifeboat
spoil ground
spool manager
status of taxpayers
steering stability
syllogisms
topo-colloform
towed mine
transaction service
triethylphosphine sulfide
tuber grafting
Tyholland
vertical abutment joint
well point system
whitetip
wood rays
Yarikou