Read the following text. Choose the best word or phrase marked A, B, C or D for each numbered blank.

　　Since the_1_of the National Environmental policies Act in 1969, the United States Congress, legislature at the federal level, has_2_a series of laws designed to prevent the air and water pollution and to_3_noise. At the same time, legislatures at the state_4_have also been active in this area, and many states have laws that are similar to the federal laws._5_, a state law must not conflict with a federal_6_or_7_an unreasonable burden on interstate commerce.

　　The city of Burbank in California adopted an ordinance_8_the nighttime takeoffs of jet aircraft between 10 p.m and 7 a.m. Lockheed owned and operated the Burbank Airport. It_9_Brubank to prevent the enforcement of the ordinance.

　　The judgment is_10_Lockheed. The federal government of the United States has passed laws_11_aviation and noise in the federal Aviation Act of 1958 and the Noise Control Act of 1972. Such legislation preempted the field and_12_state action, because _13_regulations would place an unreasonable burden on interstate commerce. If each airport had its own landing time_14_, it would be very difficult to plan flights. Moreover the bunching of flights to_15_local curfews would produce even greater noise and would increase the danger of _16_by increasing traffic _17_. From the nature of aviation_18_, a single national control was essential. As a local regulation, the_19_ prohibiting nighttime takeoffs adopted by the City of Burbank was_20_declared illegal.

　　1. A. enforcement B. enhancement C. enjoyment D. engagement

　　2. A. adapted B. adept C. adopted D. adjusted

　　3. A. subtract B. decrease C. lower D. reduce

　　4. A. standard B. level C. layer D. administration

　　5. A. therefore B. moreover C. although D. however

　　6. A. statue B. statute C. stature D. status

　　7. A. pose B. expose C. dispose D. impose

　　8. A. prohibit to B. prohibit C. prohibiting D. prohibited

　　9. A. sued B. accused C. charged D. complained

　　10. A. favorable B. unfavorable C. for D. against

　　11. A. consider B. considering C. considerate D. considerable

　　12. A. included B. involved C. excluded D. extended

　　13. A. national B. federal C. external D. local

　　14. A. plans B. schedules C. charts D. arrangements

　　15. A. stop B. escape C. avoid D. flee

　　16. A. collision B. crash C. crack D. collapse

　　17. A. number B. capacity C. airlines D. density

　　18. A. activity B. act action C. action D. movement

　　19. A. order B. ordinance C. constitution D. regulations

　　20. A. otherwise B. still C. furthermore D. therefore、