Could an arrow be a symbol of reaching your goals? Everyone is given a limited number of arrows. Use your arrows wisely and aim for what you really want. Once your arrow has been shot, there's no going back but you have one option: move on.
Almost everyone knows that plants and trees convert carbon dioxide into oxygen. We all need oxygen to breathe and survive. Every plant carries out this conversion. Some of them do this more effectively. NASA is always busy doing something.