Great changes_____ in the small city in the last 20 years.

A．have taken place

B．took place

C．had taken place

D．are happening

如果患者为精神分裂症，可能伴有的其他症状有

A．意识障碍

B．思维形式障碍

C．智能障碍

D．情感变形

E．情绪低落