A bridge is a good simile to describe friendship. Besides using a bridge, I think a belt can also be used to describe friendship. Most belts are made with a metal ring and leather, and have holes. The friendship between friends can be put into different ranks, and we can use the colours of belts to represent them. For example, red means the best friends. Purple refers to a group of fellow members, because purple is the mixture of many colours. For friends not so intimate, I choose white.
Furthermore, if the friends you make are good for you, you should get close to them and learn from their strengths. It is just like you fasten the belt tightly. On the other hand, you should get rid of the bad friends, like to loosen the belt.
Friends have quarrels and misunderstandings. They should aim at harmony in friendship. It is simply like passing through the holes on the belt – knowing each other well.
Lastly, I hope you can choose a belt – friends or friendship – that fits you wisely.