基金投资分类是对股票投资风格进行业绩评价的基础。( )
参考答案：对
解析： 对基金投资分类，才能在特定的类别中对基金的业绩进行评价。
进行预防接种，属于预防传染病措施中的（）
A.控制传染源
B.控制传播媒介
C.切断传播途径
D.保护易感者
E.消灭病原体
The students ______ busily when Miss Brown went to get a book she ______ in the office.[ ]
A. had written; left
B. were writing; has left
C. had written; had left
D. were writing; had left
