Why are there square brackets around the first letter of a word?

Ihave to write a narrative poem for an english assignment, but i can't come up with any topics/ideas for the poem. any topics ideas?

Using the charts above as references, find two words using the root below. if you need to, use your dictionary (do not use the example word given then illustrate that the word has the meaning of that root by using one of those words in a sentence. example: mon 1. admonish 2. demonstrate she admonished her children to stay away from the busy street. cap

We will be learning about animals that live in the arctic. your assignment is to find information about one animal in the arctic. be sure that you find the following information about the animal: average height and weight, appearance, diet, shelter, mating habits, and any other interesting or important facts. we will use the information that you gather in the research with an in-class project. be sure to keep track of your sources; your final project will require a works cited page. in an internet search engine, which group of keywords is most appropriate for this assignment? a) project, arctic, diet b) arctic, animals, facts c) cold, appearance, animals d) average height and weight, one animal