Some scientists think that it will take of years to make robots do most work for humans.

问题补充：

Some scientists think that it will take of years to make robots do most work for humans.

A. hundreds B. hundred C. thousand

答案：

解析：考查数词的用法。固定短语hundreds of“成百上千”、thousands of“成千上万”；如果前面没有具体的数字，常用复数加of结构表示不确切的数字。