Alexander Bain designed the first battery clock shortly before 1838. Today the term is applied to portable electric clocks which depend on a dry cell or battery for its electrical ...
A unit of measurement of one cycle per second when one radio wave passes one point in one second of time. Named in honor of Heinrich Hertz, the physicist who developed the theory ...
The process of registering your iPhone with Apple and AT&T. Until your iPhone is activated, it can only be used for emergency calls. While the first generation iPhone was ...
3 用語
