This machine is very easy . Anybody can learn to use it in a few minutes.
A. operating
B. to be operating
C. operated
D. to operate
网友回答
A. operating
B. to be operating
C. operated
(答案→)D. to operate
解析：考查非谓语动词。句意：这台机器很容易操作。任何一个人都可以在几分钟内学会使用它。operate与的逻辑主语是人，是主动关系，排除B、C；sth is easy to do...做某事很容易，故选D。