简述春秋战国各国筑长城的主要原因？

从下面方框中选择恰当的词填入短文中，使短文通顺正确。每词只用一次，有些词要用适当形式

when,  change,  difficult,  also,  help,  chance,  same,  advice,

 
Friendship(友谊) is an important part of our life. Life is always 小题1:______________ , such as moving to a new place and starting a new job. So we often need to make new friends. But some people think it  is小题2:______________to make new friends. Here is some 小题3:________________ for you. If you want to make friends, you need to go out at first instead of (代替) staying at home. You can join a club because there are many people who have common (共同的) interests. It is easy to start a new friendship if you have the 小题4:______________ interests. And you can join a sports team. It is 小题5:_____________ a great way to make new friends. After joining a club or a sports team, you still can’t make friends if you don’t talk to people. You will have a good小题6:_______________  to make a good friend if you talk to someone. 小题7:______________ you talk to people, you should be friendly and smile at them. The above(上面的) advice can 小题8:______________ you make friends. But if you want to find the true friendship, you should be honest with them.