Theoperationroomineveryhospitalhasto

問題詳情：

  The operation room in every hospital has to_____bacteria of any kind so that the patient being operated on doesn’t get infected.(感染)

A. keep free from    B. make it free from  C. to be made free with    D. be kept free from

【回答】

D

知識點：詞組 短語

題型：選擇題