問題詳情
【題組】55. We learn from the text that volunteers in the experiment _____.
(A) were patients with bad coughs
(B) were divided into the three groups
(C) received standard treatments
(D) suffered little side effects
參考答案
答案：B
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)
用户評論
【用戶】步筱昕
【年級】高三下
【評論內容】从第四段首句Ten healthy volunteers(志愿者) were given theobromine, codeine or placebo, a pill that contains no medicine, during the experiment.可知实验中每组人吃一种所给的物品才能看出止咳的效果，故需要三组志愿者。