根据短文内容的理解，选择正确答案。
Friendship is the most important thing in the world. But how do you find a real friendship and keep it?
An American writer tells young students some smart ways to find friends. He says finding friendship is just like planting a tree. You plant the seed(种子) and take care of(照顾) it to make it grow(生长).
First, to make friends, you must be kind and friendly to others. You should learn to smile at others and try to make a stranger(陌生人) feel at home. You should think more of others than of yourself.
Second, friends should negotiate(商量). When you don't agree with someone, please discuss with him or her. But even the best friends can fight. After the fight, you have to talk to him or her. If he or she doesn't want to talk, you could write a letter. Tell him or her how you are feeling, and tell him or her why you did this or that.
Finally, if he or she leaves you when you are in trouble, never believe in him or her. And never leave your friend when he or she is in trouble. Remember, a friend in need is a friend indeed.
