液体石油沥青分为（）三类。
A、快凝
B、中凝
C、慢凝
D、终凝
参考答案：A, B, C
菱形ABCD的相对顶点A（1，-2），C（-2，-3），则对角线BD所在的直线方程为（ ）
A．3x+y+4=0
B．3x+y-4=0
C．3x-y+1=0
D．3x-y-1=0
How can exercise help make a person look younger A. By making them feel happier. B. It helps keep type Ⅱ muscle fibres in better condition. C. It increases oxygen flow.
