----- Nội dung ảnh ----- I. Read the passage and choose the correct answer to fill in each blank.
There are a lot of pastimes that young people like, and one of (1) **them** is mountain climbing. It is an active leisure activity that people can do either indoors or outdoors. If you go climbing outdoors, it is a great way to (2) **increase** your strength and enjoy nature at the same time. You can even set up your own climbing wall in your backyard of (3) **inside** your home. This way you don’t have to go out and still can (4) **keep** fit and enjoy the activity. So how can you start mountain climbing? Many people take a class to earn how to climb and use their equipment (5) **effectively**. Others join climbing clubs to make new friends with the same interest and go climbing together. If you are an active person and like outdoor activities, (6) **why** don’t you try this activity?