Real policemen hardly recognize any resemblance (类同之处)between their lives and what they see on TV--if they ever get home in time. There are similarities, of course, but the cops(警官) don't think much of them. The first difference is that a policeman's real life revolves round the law. Most of his training is in criminal law. He has to know exactly what actions are crimes and what evidence can be used to prove them in court. He has to know nearly as much law as a professional lawyer, and what is more, he has to apply it on his feet, in the dark and rain, running down an alley after someone he wants to talk to. Little of his time is spent in chatting to scanty-clad ([穿衣不多的) ladies or in dramatic confrontations with desperate criminals. He will spend most of his working life typing millions of words on thousands of forms about hundreds of sad, unimportant people who are guilt or not--of stupid, petty crimes. It is essential for a policeman to be .trained in criminal law ______.