Прочитайте текст и выполните задания.
A cordless telephone
1. Cordless phones first appeared around 1980. George Sweigert, an amateur radio operator and inventor from Cleveland, Ohio, is largely recognized as the father of the cordless phone. A cordless telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station (which has the handset cradle). The base station is on the subscriber premises, and attaches to the telephone network the same way a corded telephone does.
2. The base station on subscriber premises is what differentiates a cordless telephone from a mobile telephone. Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handover, various advanced features, such as data-transfer and even, on a limited scale, international roaming. In these models, base stations are maintained by a commercial mobile network operator and users subscribe to the service.
3. Cordless phones can operate without a power cord or cable attached to a fixed electricity supply such as an outlet, generator, or other centralized power source, allowing greater mobility. But unlike a corded telephone, a cordless one needs mains electricity to power the base station. The cordless handset is powered by a rechargeable battery, which is charged when the handset sits in its cradle.
Определите, какое утверждение соответствует содержанию текста.