A. 恩氟烷2.20%,异氟烷1.57% B. 恩氟烷1.15%,异氟烷1.68% C. 恩氟烷1.09%,异氟烷0.75% D. 恩氟烷0.67%,异氟烷0.46% E. 恩氟烷1.68%,异氟烷1.15%