Were there a subway in Shenzhen 30 years ago?

Were there a subway in Shenzhen 30 years ago? There was a subway 50 years ago? THere were no subway 5 years ago (改错) Are there many factories in shenzhen 50 years ago no,there a There was no a subway in the city 10 years ago.哪里错了 用was there提问用什么回答?was there a subway in shenzhen in 2004 50 years ago,There ( )no subway are there many factories in shenzhen 50 years ago?这句话错在哪里? There were no tall buildings in Shanghai many years ago. There were __tall buildings in our hometown many years ago. bridges,few,there,ago,were,a,50,years (There was no a subway ij the city 10years ago)有什麼错误麼?