When do you think of a forest, what do you see? Just trees Or do you see many other things, such as singing birds, colorful plants and wild flowers?
The forest is a whole world of its own. It is full of many different living things (生物). But even thoughthey are all different, they have one thing in common: they all need each other in order to live on. 
The trees feed the forest "people" by making food in their leaves; by using sunlight to join water and minerals(矿物) from the soil and air. Their deep network of roots Joins the soil together and stops it from  dying out, making it possible for living things to live in it. Human beings (人类) are like the living things in the forest. We need one another in order to live. We need the farmers to grow our food, railroad and truck drivers to bring it to our shops and clerks (售货员) to sell it to us. We need people to prepare our food and
cook it and others to take our waste things away. Then, of course, we need doctors, nurses, government  leaders, mailmen, telephone operators, and many others. We also need other human beings in another way. 
We need people for friendship, to talk over our problems, exchange ideas. Think how lonely and unhappy you would be if you lived all alone. 
Life is a matter of giving and taking. We need to help other people as much as we need other people to help us. Think what a good feeling you have when you have done something for someone else. You know,  being a volunteer is so great!
根据短文内容，判断下列句子正误。正确的用“A”表示，不正确的用“B”表示。
According to the text, different things live on the soil and air.
The water and minerals join from the soil and air by using sunlight.
According to the writer, human beings need only farmers.
When I have done something for someone else, I feel happy.
According to the passage, everyone needs friends.