Shared﹣bikes are very popular in some big cities．（改为感叹句）
shared﹣bikes are in some big cities!
China has a population of 1.37billion．（对划线部分提问）
the population of China？
She must be a doctor， ？（完成反意疑问句）
"Are you free to come to my place this Saturday？"Aaron asked me．（改为间接引语）
Aaron asked me free to go to his place that Saturday．
The scientists released the picture of a black hole to the world on April 10．（改为被动语态）
The picture of a black hole to the world by the scientists on April 10．
I have no idea how I can operate the new washing machine．（改为简单句）
I have no idea operate the new washing machine．