Alaska and Bark Beetles
Paragraph1：Over the twentieth century,global temperatures incread by an average of about0.7degrees Celsius,but some places have warmed a lot more than this,and other places have warmed less.The temperature increas have been enough to trigger changes in ecosystems all over the world,especially in places where the warming has been the greatest.In some places,the changes have been subtle,perhaps a slight shift in vegetation that only a careful obrver would notice.In other cas, small changes in climate have sparked a chain of larger effects,leading to massive changes.
1..The word subtle in the passage is clost in meaning to
○limited
○unimportant
○not obvious
○gradual
Paragraph2：The biggest climate-caud ecosystem shifts today are happening at the world's most northern latitudes,where the temperature over the last century has been rising about two times faster than the global average.In the northernmost state of the United States,Alaska,for example,warming has paved the way for a spike in the numbers of spruce bark beetles.Bark beetles have been a pest to Alaskan white spruce trees for thousands of years,but their numbers were held in check by the cold climate, which forced the incts to hide in the bark of individual trees for most of the year.As the length of the warm ason incread over the1980s and1990s,however,bark beetles had more time to fly from one tree to the next,burrow,and lay their eggs between the bark and the wood.The beetles had another thing going for them,too:a multi-year drought had weakened many of the spruce trees,leaving them vulnerable to attack.In the mid-1990s,the bark beetle population exploded,and over the next few years the pests wiped out white spruce forests over an area the size of the U.S. state of Connecticut.In the years since,the combined forces of a longer inct-breeding ason and forest management practices that left forests overcrowded gave way to similar epidemics farther south.Large swaths of pine and spruce have been destroyed by incts in veral other parts of the United States.
2..The phra paved the way for in the passage is clost in meaning to
○come together with
○made possible
○incread the intensity of
○made absolutely certain
3..The phra wiped out in the passage is clost in meaning to
○threatened
○spread through
○killed off
4..Paragraph2suggests that the warming of the Alaskan climate affected bark beetles in which of the following ways
○By making it possible for a beetle to deposit its eggs in a greater number of trees
○By making it possible for beetles to survive in the bark of trees for longer lengths of time
○By making it unnecessary for a beetle to protect its eggs by laying them between the bark and the wood
○By increasing the number of spruce trees,thereby providing the beetles with far more places to live
5..According to paragraph2,all of the following contributed to the destruction of forests in different parts of the United States EXCEPT
○a drought that had lasted for veral years
○a lack of forest management practices
○overcrowding in forests
梦见很多蛇是什么意思
○a huge increa in spruce tree pest populations土豆丝怎么切
Paragraph3：In the late1990s,the effects of the bark beetle epidemic rippled throughout Alaska's white spruce ecosystem and affected virtually every population of living organisms,but not all of the impacts were negative.Fewer spruce trees meant a sunnier area in the forest below the treetops,which allowed grass to move in and take hold.The grass,in turn,changed the soil tempe
rature,making the environment more friendly for some other types of vegetation.Animals that feed on grass, including moo,elk,and some birds,also benefited.But the beetle infestation was bad news for organisms that rely on white spruce for their habitat,like hawks,owls, red squirrels,and voles.Voles a type of small,moulike rodent are an especially vital part of the ecosystem becau they help spread mycorrhizal fungi,which attach to the roots of plants and help them take in water and nutrients.Voles are also an important food for a number of predators.
6..Which of the following statements most accurately describes the relationship of paragraph3to paragraph2
○Paragraph2explains the caus of the spruce bark beetle epidemic in Alaska,and paragraph3discuss the chain of events that occurred as a result of that epidemic.
○Paragraph2shows that warming air temperatures can affect a large number of species,and paragraph3shows that warming soil temperatures can have even greater effects.
○Paragraph2discuss one explanation for the disappearance of spruce trees from a part of Alaska,but paragraph3shows that an alternative explanation is more likely to be correct.
○Paragraph2describes the negative conquences of climate warming for some species,but paragraph3shows that there are also some positive conquences for the same species.
7..According to paragraph3,which of the following effects did the bark beetle epidemic have on moo,elk,and some birds
○The epidemic incread the availability of water for the animals.
○The epidemic incread the availability of food for the animals.
○The epidemic destroyed the habitat of the animals.
○The epidemic meant that the animals experienced more competition from hawks, owls,red squirrels,and voles.深夜电台情感独白文本
8..According to paragraph3,a decline in the vole population in Alaska may have which TWO of the following conquences To receive credit,you must lect TWO answer choices.
○Some predators may have less to eat.
○Hawk and red squirrel populations may be more successful.
○Plants may find it more difficult to absorb water and nutrients.
○Mycorrhizal fungi numbers may increa.
Paragraph4：█Ecosystem changes always hurt some living creatures and help others. It's hard to say,therefore,whether a change is good or bad overall.█Instead, ecologists(people who study ecosystems)often focus on the impacts on a single species:for instance,us.█In the short term,the Alaskan spruce beetle epidemic supplied a lot of people with firewood,but only by destroying tons of otherwi valuable timber and threatening the livelihoods of loggers.█And no one knows for sure what the long-term impacts on the forest will be.Ecosystems tend to return to their previous states after disturbances like pest outbreaks,fires,or major storm events, but if the Alaskan spruce ecosystem is disturbed too often or too much,it might shift to a different type of forest,a woodland,or a grassland instead.
睡不着的时候
9..Which of the ntences below best express the esntial information in the highlighted ntence in the passage Incorrect choices change the meaning in important ways or leave out esntial information.
○Ecosystems like the spruce ecosystem in Alaska tend to return to their previous states after disturb
ances such as pest outbreaks,fires,or major storm events.
○While ecosystems tend to return to their previous states after disturbances,the Alaskan spruce ecosystem might not if it is disturbed too often or too much.
○Ecosystems tend to return to their previous states after disturbances,so Alaska might again become covered with woodlands or grasslands.
○After certain types of disturbances such as pest outbreaks,ecosystems do not always
return to their previous states but shift to being woodlands or grasslands instead. Paragraph5：In extreme cas,major assaults on ecosystems can lead to a total collap in which the ecosystem doesn't bounce back to the way it was or transition to a new,healthy state.The result is an area with very little life;in the oceans,biologists refer to the areas as dead zones.One such example is the coral reef die-off that happened in the Indian Ocean in the late1990s.
10..The phra assaults on in the passage is clost in meaning to
○imbalances in
○changes in
○problems for
○attacks on
11..In paragraph5,coral reefs in the Indian Ocean are prented as an example of which of the following
○Ecosystems that totally collapd
○Ecosystems that transitioned to a new,healthy state
○Ecosystems that bounced back to the way they were
○Ecosystems that were affected by a nearby dead zone
12..The passage provides an answer to which of the following questions
○Why has the temperature at northern latitudes been rising faster than the global average
○Why did corals in the Indian Ocean die off in the late1990s
○What types of vegetation benefited from the change in soil temperatures in Alaska ○What were some of the effects of the bark beetle epidemic for humans
13..Look at the four squares that indicate where the following ntence could be added to the passage.
修路
But even from this limited perspective,the answer is not completely straightforward. Where would the ntence best fit Click on a square to add the ntence to the passage.
Paragraph4：█Ecosystem changes always hurt some living creatures and help others. It's hard to say,therefore,whether a change is good or bad overall.█Instead, ecologists(people who study ecosystems)often focus on the impacts on a single species:for instance,us.█In the short term,the Alaskan spruce beetle epidemic supplied a lot of people with firewood,but only by destroying tons of otherwi valuable timber and threatening the livelihoods of loggers.█And no one knows for sure what the long-term impacts on the forest will be.Ecosystems tend to return to their previous states after disturbances like pest outbreaks,fires,or major storm events, but if the Alaskan spruce ecosystem is disturbed too often or too much,it might shift to a different type of forest,a woodland,or a grassland instead.
矣字草书
14..Drag your choices to the spaces where they belong.To review the passage,click on View Text.知母的作用与功效
Answer Choices
○Global warming has led to changes in ecosystems all over the world,with ecosystems at northern latitudes being affected the most.
○A longer warm ason in Alaska caud a sharp increa in the number of bark beetles,leading to the destruction of spruce forests,which in turn riously affected many other species.
破口大骂的意思
○Sometimes ecosystems are able to recover from disturbances or to develop into different,but healthy,systems,but in extreme cas,they may collap completely.
○The loss of spruce forests caud an epidemic in mycorrhizal fungi,and the fungi damaged the roots of many plants,making them unable to take in water and nutrients.○Whereas some types of changes are good for the majority of species in an ecosystem,ecologists believe that most disturbances to ecosystems are bad overall.
○Coral reefs may die off as a result of the global increa in temperatures,but after a transition period as a dead zone,they are able to return to their original state.
Motor Development in Children
Paragrah1：Control over one's motor behavior ranks among the infant's greatest achievements.Psychologists who study the acquisition of motor skills in children find it uful to distinguish between gross motor development,that is,motor skills which help children to get around in their environment such as crawling and walking,and fine motor development,which refers to smaller movement quences like reaching and grasping.
1..According to paragraph1,the distinction between gross motor development and fine motor development is bad primarily on
○how much control the infant has over the motor skills
○when the motor skills are developed
○the size of the movement quences involved
○the ufulness of the movement quences involved
Paragrah2：The development of motor skills has implications beyond simply learning how to perfor
m new actions:motor skills can have profound effects on other areas of development.For example,rearchers have shown that infants with locomotor experience(experience moving around their environment)were less likely to make errors while arching for hidden objects.The ability to initiate movement around one's environment stimulates the development of XXX（此处缺具体的词）,making hidden object tasks easier to solve.Psychology professor Carolyn Rovee-Collier argues that the ont of independent locomotion at around nine months old marks an important transition in memory development.Children who can move about the environment develop an understanding of locations such as here and there.Becau
