问题
选择题
I think Father would like to know _______ I’ve been up to so far, so I decide to send him a quick note.
A．which
B．why
C．what
D．how
答案
C
根据宾语从句中的谓语部分be up to(正在做)可知此处缺宾语，填上what 后表示“正在做什么”。
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