某人年龄20岁,“20”是()。
A.离散变量
B.连续变量
C.变量值
D.数值型变量
参考答案:C
---Are all telephone numbers_______ in the directory? --- Yes, all ________ Jane’s.
A.listed; including
B.listed; included
C.including; includes
D.being listed; including
泌尿系统最常见的感染途径是()。
A.淋巴道感染
B.上行感染
C.血行感染
D.直接感染
E.以上都不是