Barron's with real test

<p>I worked on Barron's big fat book. my score fluctuated around 520-580 on reading, and writing 550-600...i don't know how to further improve my score to above 600. Please identify my problem with suggestions. Thanks.</p>

<p>Reading part, sentence comp 1-4 wrongs, passage 3-5 wrong per section.
Writing part, improve sentence 2-3 wrongs, Identify error 3-4 wrongs per section.</p>

<p>PS: in Official Guide, I will get most errors in sentence comp and long passage part.</p>