车牌 

Pinyin: chē pái 
Meaning：Vehicle plate
Sentence：两位海军军官拿着两组军车车牌。Two Chinese naval officers present two sets of military vehicle plates

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车： 

Pinyin: chē
Meaning: Machine; car; a vehicle; to shape with a lathe
Radical: 车
Stokes: 4
Traditional: 車
Common words/Phrase: 
车间 [chē jiān] 【workshop】
车票 [chē piào] 【ticket】
车站 [chē zhàn] 【station】
车库 [chē kù] 【garage】
车祸 [chē huò] 【traffic accident】

牌： 

Pinyin: pái
Meaning: Plate; signboard; tablet
Radical: 片
Stokes: 12
Traditional: 牌
Common words/Phrase: 
牌子 [pái zi] 【trademark; sign】
牌号 [pái hào] 【mark】
牌照 [pái zhào] 【license plate】
牌价 [pái jià] 【list price】
牌坊 [pái fāng] 【memorial arch】