Пре­об­ра­зуй­те, если это не­об­хо­ди­мо, слово DARK так, чтобы оно грам­ма­ти­че­ски и лек­си­че­ски со­от­вет­ство­ва­ло со­дер­жа­нию тек­ста.

The main emergency telephone number in Britain is 999. The number 999 was chosen because, on the old dial phones, it was considered to be the easiest to dial in __________________ or smoke.