Despite your best attempts to convince her otherwise, your friend is very afraid of spiders and all "bugs," which to her means insects. When you note that spiders are not insects, she claims they are the same thing. You finally convince her that spiders are not insects because, for one thing, spiders .

- have two body segments joined by a pedicel.

Explanation:

As per the question, the factual description i.e. 'spiders having two body segments joined by a pedicel' helped in convincing her that 'spiders are not insect' as this fact logically establishes the credibility and validity of the claim.

However, both the 'insects' and 'spiders' are characterized as invertebrates but the insects possess six legs(three pairs) and three main body parts along with wings and antennae which are covered by a hard outer covering. The spiders, on the other hand, consists of two main body parts or segments with four pairs of legs(eight) without any antennae or wings and belong to Arachnids' group. Thus, this description logically convinces her.

answer; a cost benefit analysis;

answer; longitudinal;