问题
单项选择题
Before adding new stocks ______ your investment portfolio, why not attend one of our investment seminars, where you will be able to meet our consultants in a small group setting
A. at
B. to
C. for
D. with
答案
参考答案：B
解析：本题需选择适当的介词。根据句意，应取add A to B(把A加到B)的结构，故选(B)to。