问题
单项选择题
—Do you know what Tom does all day
—I know he spends at least as much time watching TV as he______his lessons.
A. is doing
B. does
C. spends to do
D. does doing
答案
参考答案：D
解析： does代替前面出现的谓语动词spends time doing sth，故答案为D。