给已有文件“实验中学学生花名册.txt”增加两名学生，而且不能覆盖原有的内容。 下面代码正确的是？
A： filename="实验中学学生花名册.txt" with open(filename,"w") as f: f.write("黎明\n") f.write("方芳\n")
B： filename="实验中学学生花名册.txt" with open(filename,"r") as f: f.write("黎明\n") f.write("方芳\n")
C： filename="实验中学学生花名册.txt" with open(filename,"r+") as f: f.write("黎明\n") f.write("方芳\n")
D： filename="实验中学学生花名册.txt" with open(filename,"a") as f: f.write("黎明\n") f.write("方芳\n")
正确答案：D
试卷来源：202109 青少年软件编程等级考试Python三级真题