问题补充：
—Are you busy today?
—Yes, I have homework to do.
A. a lot
B. many
C. plenty
D. much
答案：
A. a lot
B. many
C. plenty
(答案→)D. much
解析：A. a lot 很，非常，程度副词，修饰动词或是形容词 B. many许多，修饰可数名词的复数形式 C. plenty 足够的，常构成 plenty of的表达 D. much许多，修饰不可数名词；句意：你今天忙吗？是的，我有很多作业要去做。故选D
