定义类:packageutils;publicclassRep{publicstaticStringtwice(Strings){returns+s;}}再定义另一个类Demo://insertcodeherepublicclassDemo{publicstaticvoidmain(String[]args){System.out.println(twice("Hello"));}}在第一行插入哪项代码,可以使程序正常编译和执行?()
A. importutils.*;
B. importutils.Rep.*;
C. importstaticutils.Rep.twice;
D. staticimportutils.Rep.twice;