11 A set B become C remain D rest
12 A heat B energy C food D oxygen
13 A witnessed B determined C applied D calculated
14 A system B place C arrangement D equipment
15 A mentally B artificially C manually D automatically
参考答案:
1. B 2. C 3. A 4. D 5. B
6. C 7. A 8. D 9. A 10. B
11. C 12. D 13. B 14. A 15. D
