中枢神经系统儿茶酚胺类递质失活的最主要方式:
A. 稀释到引起突触后反应的阈下值浓度
B. 重摄取
C. 单胺氧化酶(MAO)降解
D. 儿茶酚胺-氧化-甲基转移酶降解
For years, doctors_______millions of patients 'lives.
A. have saved
B. are saving
C. will save
D. were saving
Allen is looking forward to ______the trade fair.
A. meet
B. meeting
C. be meeting
D. having met
Important people don’t have much free time as their work_________ their time.
A. takes away
B. takes over
C. takes up
D. takes in