Aset of technical directions is badly flawed if
a) is compared with other information, such as drawings
b) does not properly sequence information
c) has unfamiliar words that are not looked up
d) is not read thoroughly

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

- "the die is cast; i have consented to return if we are not destroyed. thus are my hopes blasted by cowardice and indecision; i come back ignorant and disappointed. it requires more philosophy than i possess to bear this injustice with patience. i have lost my hopes of utility and glory; i have lost my friend."