I do ok on ACT science passages where you have to read graphs and answer questions about data, but I struggle with the conflicting viewpoints section. How can I improve?
The best strategy for conflicting viewpoints is to write a brief summary (as in a few words or a sentence) of each passage as you read. This way, when you're answering questions, you won't have to reread entire paragraphs. If you can distill each viewpoint to its central claim, you'll be able to answer most of the questions in a less time-consuming way.
I'd also recommend saving conflicting viewpoints for last so that you don't waste too much time on it at the beginning and end up rushing yourself on sections that are easier for you. Here are some additional tips you can use on ACT Science if you need more guidance: http://blog.prepscholar.com/the-11-act-science-strategies-you-must-be-using.