问题
单项选择题
After investigation it was proved that the ______ letter was written by a teacher.
A．anonymous
B．simultaneous
C．spontaneous
D．homogeneous
答案
参考答案：A
解析： anonymous“匿名的；无名的；假名的”；anonymous letter“匿名信”；simultaneous“同时的，同时发生的”；spontaneous“自发的，不依赖人工的”；homogeneous“同类的，纯一的，均质的”。答案是A。
