독해시간에 문법 문제 나왔는데.. 괄호 친부분 어떻게 바꿔야지 올바른 문장이 되는 지 좀 알려줭;; 1. The Pickerel Frog, native to Southern Canada and the Eastern United States, should be avoided because (their) skin secretions are lethal to small animals and irritating to humans. 2. The most common form of treatment (it) is mass inoculation and chlorination of water sources. 3. People with exceptionally high intelligence quotients may not be the best employees since they become (bored of) their work unless the job is constantly changing. 4. Neither the mathematics department nor the biology department at State University requires that the students (must write) a thesis in order to graduate with a master's degree. 5. The oxygen content of Mars is not (sufficient enough) to support life as we know it. 6. Students in the United States often support themselves by babysitting, working in restaurants, or (they drive) taxicabs. 7. Those of us who have a family history of heart disease should make yearly appointments with (their) doctors. 8. Although federal support for basic research programs (are) much less than it was ten years ago, more funds are now available from the National Science Foundation. 9. (Living) in New York, apartments cost more to rent than they do in other, smaller cities. 10. This new model not only saves time but also (energy) by operation on two batteries instead of four.