It added bright colorful lights, electrictrolley cars, electric heat and refrigerators to our modern world.
它给我们现代社会增加了色彩缤纷的灯光，电车，电暖气和电冰箱。
2
Smart electrictrolley, the source and circuit diagrams, some functions have been achieved, other functions need perfect!
智能电动小车，源程序和电路图，部分功能已经实现，其他的功能还需要完善！
3
Grasshopper is a foldable electric bicycle that turns into a trolley for easy transport. The use of composite materials provides rigidity and strength.