The police have found the lost boy.为什么用have found而不是has found?

Oh dear!have you called the police? the library and the police station have steps outside翻译 why do the police sometimes have trouble understanding the people? The police have not caught the thiefl yet为什么用have,the police 不是第三人称单数吗? why will the police have a difficult time意思 The police have found the lost boy.为什么用have found而不是has found? 改为被动语态：The police have arrested the thief He was typing a letter改为被动语态：The police have arrested the thiefHe was typing a letter police后面跟have,还是has怎么看到有跟has的情况啊,The police has. tell the police the Have the police found the knife which the man was killed?错在哪 the police have the road b（ ） because of the heavy fog根据首字母填词 Police have gained the upper hand over the drug dealers in the area. the police will have a difficult time police 是复数,have也有表示复数的意思吧?have:使用于第一人称、第二人称和各人称复数 the police will have the difficult time as usual还是than usual 改错 1.The police have not got enough informations to arrest the murderer . 警方证实要逮捕那个盗贼 the police have ---------- that the theif ---- ------- ------ ------- The police have s____ the building,but they found nobody in it. The thief ran away so fast that we didn't have time to call the police.（同义句）（ ) we ( )call the police ,the thief ran away quickly.