True. By the name itself, those are the things they are supposed to do.
A bony collar forms.
The bone collar is a cuff of periosteal bone that forms around the diaphysis of the hyaline cartilage model in developing long bones. The bone collar appears during endochondral bone development to support the growing bone and help it retain its shape.
A HEV has an engine that uses electric power as well as gasoline to move. When using the electric motor, there are no CO2 emission from the car. So the overall emission should be lower on a HEV than on a purely gasoline car, since you can choose to only use electric power.
