问题：

[共享题干题]【2013年真题】（一） Toads are Arthritis and in Pain Arthritis is an illness that can cause pain and swelling in your bones. Toads, a big problemin the north of Australia, are suffering from painful arthritis in their legs and backbone, a newstudy has shown. The toads that jump the fastest are more likely to be larger and to have longerlegs. (46) __________ The large yellow toads, native to South and Central America, were introduced into thenorth-eastern Australian state of Queensland in 1935 in an attempt to stop beetles and otherinsects from destroying sugarcane crops. Now up to 200 million of the poisonous toads exist inthe country, and they are rapidly spreading through the state of Northern Territory at a rate of upto 60 krn a year. The toads can now be found across more than one million square kilometers.　(47) __________ A Venezuelan poison virus was tried in the 1990s but had to be abandoned after itwas found,to also kill native frog species. The toads have severely affected ecosystems in AustraliA. Animals, and sometimes pets,that eat the toads die immediately from their poison, and the toads themselves eat anything theycan fit inside their mouth. (48) __________ A co-author of the new study, Rick Shine, a professor at the University of Sydney, saysthat little attention has been given to the problems that toads face. Rick and his colleaguesstudied nearly 500 toads from Queens/and and the Northern Territory and found that those in thelatter state were very different. They were active, sprinting down roads and breeding quickly. According to the results of the study, the fastest toads travel nearly one kilometer a night. __________ (49)But speed and strength come at a price--arthritis of the legs and backbone due toconstant pressure placed on them. In laboratory tests, the researchers found that after about 15 minutes of hopping, arthritictoads would travel less distance with each hop (跳跃). (50) __________ These toads are soprogrammed to move, apparently, that even when in pain the toads travelled as fast and as far asthe healthy ones, continuing their relentless march across the landscape.
单选题第1题_________
A.But this advantage also has a big drawback up to 10% of the biggest toads suffer from arthriti
B.The task now facing the country is how to remove the toad
C.But arthritis didn't slow down toads outside the laborator
D.Toads with longer legs move faster and travel longer distances while the others are being left behin
E.Toads are not built to be road runners -- they are built to sit around ponds and wetarea
F.Furthermore, they soon take over the natural habitats of Australia's native specie