2．The koala is one of Australia's most treasured creatures，which is a lovely little creature．But now，it is in big trouble．
Affected by habitat （栖居地） loss and climate change，like many other uniquely Australian animals，koalas are being squeezed into smaller regions．But at present，it is a deadly disease，a somewhat silent killer that causes a further decline in the koala population，that is worrying many scientists about the fate of the koala．
The killer is Chlamydia，which has caused symptoms in up to 50percent of the wild koalas，with probably even more infected （感染） but not showing symptoms．It has been particularly severe in Queensland，where nearly all koalas are infected．The disease causes many symptoms including eye infections，which can lead to blindness，making it difficult for them to find their primary food．
Treating Chlamydia in wild koalas is a challenge．There is no treatment available for it．Only a small percentage of the animals can be treated successfully and returned to the wild．Besides，there is no national plan in Australia to save the koala；it is up to each region to make management plans for its koala population．
The good news is that researchers are working to test a vaccine （疫苗） that would help prevent further spread．If all goes well，plans can be carried out to distribute the vaccil1e more widely．But it's impossible to vaccinate all wild koalas．
Another possibility would be to make vaccine distribution a routi11e part of treatment for the thousands of koalas brought into care centers every year after they are injured by cars or dogs．
While it is a combination of problems that are affecting the wild koala population，many experts believe this vaccine would be an important step in helping koalas survive longer．It may buy enough time to give researchers a chance to solve some of the other problems facing Australia's koalas．
71．Which isn't considered the main cause of koala's population decline？B
A．Habitat loss．
B．Injuries from cars and dogs．
C．Climate change．
D．A deadly disease．
72．The third paragraph mainly tells usA．
A．the serious result Chlamydia has caused to the koala
B．Chlamydia affected the koala only in particular regions
C．the most serious symptom of Chlamydia is eye infections
D．Chla1nydia can seriously affect koala's primary food
73．The underlined word"it"in the fourth paragraph probably refers toB．
A．the koala B．Chlamydia C．national plan D．eye infection
74．We can learn from the text that the vaccineD．
A．would cure the killer Chlamydia quite effectively
B．would only be distributed in koala care centers
C．has already been put into practical use in Australia
D．cannot be distributed to all the infected koalas
75．It can be inferred from the text thatC．
A．a national plan for saving koalas will be made soon in Australia
B．koala population is declining only in a few regions
C．researchers need enough time to so1ve the koala problems
D．experts have lost the best chance to save the infected koalas．
分析 文章讲述的是考拉所面临的严重问题，栖息地和气候变化，尤其是一种特殊的疾病对考拉的影响．
解答 71．B 细节理解题．根据第二段Affected by habitat （栖居地） loss and climate change，以及第三段The killer is Chlamydia可知ACD是主要原因，而B"汽车和狗的伤害"则不是．故选B．
72．A 段落大意题．这一段讲述的是衣原体对考拉造成的严重后果．故选A
73．B 词义猜测题．根据第三段的句子Treating Chlamydia in wild koalasis a challenge可知，治疗野生的考拉的衣原体是有挑战的，后面说没有它的疗法，it 指的是Chlamydia，故选B．
74．D 细节理解题．根据倒数第三段最后一句But it's impossible to vaccinate （给注射疫苗） all wild koalas．可知疫苗分配给所有被感染的考拉是不可能的，故选D．
75．C 推理判断题．根据文章最后一句It may be enough time to giveresearchers a chance to solve some of the other problems facing Austalia'skoalas．可知研究人员需要足够的时间，解决考拉的问题，故选C．
点评 本文是科教类阅读，主要考查细节理解题和推理判断题．在做细节理解题时，首先根据题目要求迅速在文章里找出相应的段落、句子或短语．认真比较选项和文中细节的区别，在做推理判断题时不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
