问题补充：
It is reported that people in the world are suffering from the H1N1 flu.
A. ten thousand of
B. ten thousands
C. thousands of
D. ten thousands of
答案：
A. ten thousand of
B. ten thousands
(答案→)C. thousands of
D. ten thousands of
解析：句意：据报道世界上有数千万人患病于H1N1流感。分析数词的用法：在具体的数词后，数量单位不能接s，如一万人为ten thousand people；而表示大约的数字后要接s,如大约数千万人为thousands of people。故选C
