-12. The security of the whole operation has been jeopardized by thin carelessness. A. showed C. secured B. threatened D. hidden 13. He is a rebellious boy. He always likes disobeying rules. A. kind C. rule breaking B. clever D. normal 14. Teachers should safeguard their students from bad habits. A. take C. teach B. show D. protect 15. This text book of English is quite out-of-date. A. is being used C. modern D. recent B. no longer used 16. I am told he has got into hot water A. became rich C. into trouble B. into a feast D. become jubilant