单选题
To: Regional Store Managers From: Anna Stanton, Quality Control Manager Subject: Recall of Blue Canyon cheese My department has been alerted (38) the food and health authority. They have identified production irregularities in some batches of Blue Canyon cheese. Although this does not represent a severe health hazard, Blue Canyon has decided to recall all products from distribution centers and retail outlets across the country. Initial reports suggest that the (39) of the problem may have been the use of improperly treated water at the production plant. Production of Blue Canyon products will not resume until the health inspection authorities (40) their investigation. Please (41) your staff to remove all Blue Canyon products immediately and to post copies of the enclosed warning notice where the products were displayed in your store. If you have any questions, please call my office directly. Yours sincerely, Anna Stanton Quality Control Manager
单选题
A. with B. by C. from D. to
【正确答案】
B
【答案解析】需要指出动作的施动者时(本题中为the food and health authority)．在被动语态的动词后加介词by。选项(A)with可以表示方式，选项(D)to可以表示宾语，选项(C)from可以表示位置、方向或地点。
单选题
A. cause B. effect C. reason D. outcome
【正确答案】
A
【答案解析】由于题空所在句子的后半部分指出了导致问题的可能根源，所以在这个语境下，能与短语of the problem进行逻辑搭配的是选项(A)cause(原因，起因)。选项(B)结果、选项(C)理由、选项(D)结果均不能表达这种意思。
单选题
A. is going to complete B. is completing C. will complete D. complete