CREATE (beijing: City {name:"beijing"} ),
(shanghai: City {name:"shanghai"} ),
(qingdao: City {name:"qingdao"} ), 
(zhengzhou: City {name:"zhengzhou"} ), 
(xining: City {name:"xining"} ),
(xian: City {name:"xian"} ),
(xiamen: City {name:"xiamen"} ),
(guangzhou: City {name:"guangzhou"} ),
(zhuhai: City {name:"zhuhai"} ),
(guilin: City {name:"guilin"} ),
(kunming: City {name:"kunming"} ),
(chengdu: City {name:"chengdu"} ),
(xizang: City {name:"xizang"} ),
(beijing)-[:KNOWS]->(qingdao),
(shanghai)-[:KNOWS]->(guangzhou),
(guangzhou)-[:KNOWS]->(xiamen),
(shanghai)-[:KNOWS]->(zhengzhou),
(zhengzhou)-[:KNOWS]->(qingdao),
(beijing)-[:KNOWS]->(xian),
(xining)-[:KNOWS]->(xian),
(xian)-[:KNOWS]->(chengdu),
(chengdu)-[:KNOWS]->(xizang),
(zhengzhou)-[:KNOWS]->(kunming),
(guangzhou)-[:KNOWS]->(zhuhai),
(zhuhai)-[:KNOWS]->(guilin),
(beijing)-[:KNOWS]->(guangzhou)