Why does the author of this passage put some terms in bold type?

Ineed . (1) chimpanzees, skillful tool-users, use several objects found in their environment as tools. (2) first of all, they use sticks. (3) they have been seen inserting carefully trimmed sticks into termite mounds and then withdrawing the sticks and eating the termites that cling to them; they also are known to use sticks to steal honey from beehives. (4) in addition, chimps use leaves in a variety of ingenious ways. (5) for example, they have been seen rolling leaves into cones to use as drinking cups, dampening them and using them to clean their bodies, and chewing them until they can serve as sponges. (6) finally, chimpanzees have been observed using stones to crack open nuts. 1. in general, the major details of this paragraph are a. ways chimpanzees learn to use objects as tools. b. reasons chimpanzees use objects as tools. c. examples of objects that chimpanzees use as tools. d. ingenious ways that chimpanzees use leaves.

Is the sentence “ironically, although approximately seventy-one percent of the earth is covered by water, thirty-three percent of its land area is desert.” a phrase or a clause?

What does tyler tell his boss to do after firing him