题目

The retiring teacher made a speech _______ she thanked the class for the cooperation.A.which B.of which C.in which D.that 答案：【答案】C【解析】考查介词+which引导的定语从句。句意：这位即将退休的老师做了一场演讲，在演讲中她感谢全班同学的合作。分析句子结构可知，此处为定语从句修饰先行词speech，把先行词代入到从句中可得到she thanked the class for the cooperation in the speech, 因此从句中缺地点状语，因此应用in which或where 设集合A＝{(x，y)||x|＋|y|≤2}，B＝{(x，y)∈A|y≤x2}，从集合A中随机地取出一个元素P(x，y)，则P(x，y)∈B的概率是 [　　] A． B． C． D．