题目

From her knowledge of Douglas's habits，she feels sure that the attacker last night ___________Douglas.A. mustn't have been B. can't have beenC. shouldn't have been D. wouldn't have been 答案：【答案】B【解析】考查情态动词+完成式。句意：从她的Douglas的习惯知识，她觉得昨晚的攻击者不可能是Douglas。根据句中feels sure 和last night可知，这是对过去事情有把握的否定推测。固定结构：can’t have done“不可能做了某事”，表示对过去有把握的否定推测。故选B。下列物质不能为人类生命活动提供能量的是（ ）A．米饭B．水C．鸡蛋D．花生油