阿摩線上測驗
10 To test a new painkiller, researchers gave it to one group of volunteers, while a second group got a ________, identical in appearance to the new medicine but with no built-in power to relieve pain.
(A) placement
(B) placebo
(C) placenta
(D) plasma
答案：登入後查看
統計： A(0), B(0), C(0), D(1), E(0) #3735462
統計： A(0), B(0), C(0), D(1), E(0) #3735462
