keep one's head
keep calm during some emergency （在紧急情况下）保持镇静
*That housewife kept herhead and telephoned the fire department immediately；otherwise the whole house might burn down．那个家庭主妇头脑冷静，并且立即给消防队打电话，否则整个房子就会烧光了。
*Above all，keep your head in the face of danger．最主要的是，面临危险要镇静。
*When Jim heard the firealarm he kept his head and looked for the nearest exit．当吉姆听到火警铃声时，他保持镇定，寻找最近的出口。
lose one's head
become upset； lose one's selfcontrol惊慌失措；失去控制
*He is liable to losehis head．他容易发脾气。
*If the politicianhadn't gotten angry and lost his head，henever would have slandered his opponent．如果那个政治家不是生气并且失去控制的话，他是决不会诽谤他的反对者的。
*Seeing the other carcoming toward him at such speed，John lost his head anddrove up over the curb into a tree．看见另一部小汽车飞速向他开过来，约翰惊慌失措把车子开到路边的镶边石上，撞到树上去了。
*She lost her head whenshe found the house on fire．她发现房子着火时惊慌失措。
