問題詳情

【題組】43 What did Dr. Hernandez and his team look for to detect signs of trouble in sewers ?
(A)hydrogen
(B) hydrogen sulphide  
(C)carbon dioxide 
(D) hydrogen dioxide 

參考答案

答案：B
難度：適中0.640449
統計：A(7),B(57),C(9),D(5),E(0)