Hello,
i took the test last year.
when i started writing the second part of the exam, i had no idea what i needed to write.
plus, the subject was something that i had no experience with nor previous education.
so i kept to the 5 paragraph essay system.
1st paragraph; Introduction with Thesis Statement
2nd, 3rd, 4th paragraphs: Body with strong Topics Sentences
5th Paragraph: Conclusion with restating Thesis Statement
for each paragraph, i only had one sentence, which was the topic sentence.
i have nothing to back it up.
though i only wrote something like 9 sentences, i got and 6.5 on the writing section of the test.
i think they are only looking for structure.
good luck. i hope this helps