Which is the telephone the computer or the light bulb?A. useful B. more usefulC. most u

问题补充：

Which is , the telephone, the computer or the light bulb?

A. useful

B. more useful

C. most useful

D. the most useful

答案：

A. useful

B. more useful

C. most useful

(答案→)D. the most useful

解析：句意：哪一个最有用，电话，电脑还是电灯泡？结合语境可知本句中表示在多个中进行对比，故用形容词的最高级，选D。