顺序关系指相邻两种活动按顺序进行，如前一活动结束，后一活动马上开始称为（）
A.间隔
B.紧连
C.搭连
D.平行
参考答案：B
-- Which floor does John live on?
-- He lives on the __________floor of the building.
A．five
B．fifth
C．fifteen
D．fifty
