In the future senior citizens will be able to go anywhere using high-tech cameras to the

问题补充：

In the future, senior citizens will be able to go anywhere using high-tech cameras to their head.

A. attaching

B. attached

C. to attach

D. attaches

答案：

A. attaching

(答案→)B. attached

C. to attach

D. attaches

解析：考查非谓语动词用法。Camera与attach构成被动关系，使用过去分词。