Last summer we visited Yellowstone National Park. It is very lively and {#blank#}1{#/blank#}.We wanted to see the beautiful views there. It is the oldest national park in the world.{#blank#}2{#/blank#} visitors must be careful not to leave food in their tents at night，because there are {#blank#}3{#/blank#}of bears in the park in the season. If the bears are {#blank#}4{#/blank#}, they might come into the tent to eat it. So people must take care of {#blank#}5{#/blank#} at night. It is important to us.