根据语境从方框中选出恰当的单词填空，有的需要变换形式。
clear, nature, sign, beside, loud
1. There is a big supermarket ________ the zoo.
2. Let’s go to the park after the rain stops and the clouds ________.
3. Bob, could you please turn down the radio? It’s too _______
_.
4. What do those road ________ mean, Dad?
5. How many kinds of animals and plants live in the ________ world?