问题
单项选择题
Such benefits are predicted to be greatest for Germany and Austria, ______ retain the closest ties with the candidate countries.
A．which
B．where
C．who
D．that
答案
参考答案：A
解析： 结构识别
此句所填之词应为一个引导非限定性定语从句的关系代词，因与主句用逗号分开且指代物，因此A为答案。