题目内容：

IV. Choose the right sentences to complete the article.

If you go into the forest with friends, stay with them. 1.If you get lost, this is what you should do. Sit down and stay where you are. 2.You can help them find you by staying in one place. There is another way to help your friends or other people to find you. You can shout or whistle (吹口哨) three times. Stop. Then shout or whistle three times again.  3.

    Keep up shouting or whistling. Always three times together. When people hear you, they will know that you are not just making a noise for fun.4.They will give you two shouts or two whistles. When a signal is given twice, it is an answer to a call for help. 

     If you don't think that you will get help before night comes, try to make a little house with branches(树枝). 5.

     When you need some water, you have to leave your little branch house to look for it. Don't just walk away. Pick off small branches and drop them as you walk in order to go back again easily. When you are lost, the most important thing to do is to stay in one place.