They are animal-like because they are heterotrophs, and are capable of moving
D. cells are the basic unit of structure and function in living things
Green plants and trees use photosynthesis to make food from sunlight, carbon dioxide and water in the atmosphere: It is their primary source of energy. The importance of photosynthesis in our life is the oxygen it produces. Without photosynthesis there would be little to no oxygen on the planet.
The easiest example here is a computer/laptop... e.g. when the CD-ROM is spinning when you are perhaps playing a movie, the kinetic energy causes friction, which results in heat. All computers need a fan to prevent them over-heating for this very reason. Therefore heat is lost and energy is wasted.
Another example is a lightbulb. When a light is switched on and left for a long time, the current flowing through the filament (the thin bit of wire in the bulb) causes heating (due to electron-ion collisions but you may not need to know that) so energy is wasted as thermal energy instead of light energy.
These are just a few examples but other ones you could use are tv screens, kettles, toasters, etc :)
