—Where did the professor made the speech yesterday?
—It was in the hall ________ the students often have a meeting ________ the professor made the speech yesterday.
A：that; which
B：where; that
C：that; when
D：where; when
— I'm sorry to hear that.
对下面这首词的赏析，不恰当的一项是（ ）
武陵春
李清照
风住尘香花已尽，日晚倦梳头。
物是人非事事休，欲语泪先流。
闻说双溪春尚好，也拟泛轻舟，
只恐双溪舴艋舟，载不动许多愁。
新航路的开辟使世界市场开始形成，最能够说明这一结论的是（ ）
空气的成分中，体积分数最大的是
已知直线（1﹣a）x+（a+1）y﹣4（a+1）=0（其中a为实数）过定点P，点Q在函数y=x+1x的图象上，则PQ连线的斜率的取值范围是____
