16. When the children plan to send a letter to the person who leaves the gifts, they are prevented. How does this happen? Who does it, and why might they do so?

The children are prevented by sending the letter to the person who leaves the gifts because Mr. Radley filled up the hole with cement. He says he plugged the tree up because it was sick, but i think it was because Mr. Radley wanted to stop communication between the children and BOO.