The author of the report __________________ (对医院的问题非常了解) because he has been working there for many years.

填空题_____________ (为了最大限度减少窃案发生的可能性), they install a good alarm system.

单项选择题A．have recommendedB．has recommendedC．recommendedD．recommending

填空题The father __________________ (哀求) his son to be less trouble to his mother.

填空题The murderer ____________ (混在人群当中)with an attempt to shoot at the Prime Minister whenever he seized a chance.

填空题Scientists will have to ______________ (提出提高世界粮食供应量的新方法).