Alligators have always been the most dangerous predators of the Florida Everglades, (31) .................. their long-held position is now being challenged by a growing population of Burmese pythons.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35

Alligators have always been the most dangerous predators of the Florida Everglades, (31) .................. their long-held position is now being challenged by a growing population of Burmese pythons.

The Burmese python, a giant snake measuring up to 20 feet long and weighing up to 200 pounds, is  very popular among exotic pet owners. However, as the (32) .................. snakes grow, they become more difficult to cafe and handle. To avoid dealing with the snakes, the owners irresponsibly release them into the wild. (33) .................. the Everglades is quite similar to the python’s native environment of Southeast Asia, they survive and prosper without difficulty.

The issue with the Burmese pythons is their choice of meals. They eat alligators and endangered birds, which creates a strain on an already (34) .................. ecosystem. Recently a 13-foot long Burmese python was found with a 5-foot alligator bursting from its stomach. They python died trying to eat the alligator but a larger one would have easily won the struggle. With over 30,000 Burmese pythons now living in the Everglades, a solution to stop this invasive species is necessary. If the pythons are (35) .................. unchecked, there is a strong possibility they will wipe out a variety of species necessary for the functioning of the Everglades ecosystem.

(Source: * Master TOEFL Junior*, Hahn (2015)

(31) .................

• A. but
• B. so
• C. because
• D. since