A computer cannot remember who_____; it simply does what _________.

A．will use it; it is told

B．uses it; it has told

C．used it; it is told

D．has used it; it told

为游客出现冻疮时，可利用手掌的体温对其加热，方法是用手掌轻轻的按摩、揉搓，渐渐地加压，反复几次加温后，再涂上冻伤药。( )