There are some important characteristics that a robot must have.These characteristics might help you to decide what is and what is not a robot. It will also help you to decide what you will need to build into a machine before it can be considered as a robot.

老师：黑体字句子的前面有与其结构相似的的并列句（These characteristics might help you to decide what is and what is not a robot，该句的主语是these characteristics）

黑体字的主语it是否用错？能否改为代词they.

谢谢帮助，顺祝老师和网友中秋快乐~~