And mobile phones have evolved from the five or six kg "portables," heavy as a briefcase, which included a battery pack, to the current "hand-held" types, whose weight is not very different from an ordinary receiver. Some are even smaller than receivers, and can be carried in a pocket; from a little ways off one looks like a notebook.
而行動電話則從附帶著一個電池底座，體積如公事包般碩大，重達五、六公斤的「攜帶型」，演變到目前體積和重量都與一般電話聽筒相差不多的「手持型」，有些機型甚至比一般聽筒還小，可摺起來放在口袋中，遠遠看去，還以為是小筆記本。