For the difficulties in reading and taking notes on the Internet, I think the biggest thing is that I can’t mark the places in the article that I don’t understand while reading. Usually when I read the book, I will mark what I don’t understand. Usually I will use the pen to underline these words or circle them, then I will look at the meaning of these words and simply record them in the margins on the side. I believe this will be very helpful for my later reading, because when I don’t know, I can go back and see what they mean. But I can’t easily label it on the Internet. I can only write what they mean on paper. When I come back later, I may not be able to find the piece of paper or I don’t know which online article corresponds to the explanation on the paper. I checked it online and found that there are some software that can be used to read and mark at the same time, such as goodreader, PDFExpert, and Office Lans. Most of these softwares are on the iPad, and they are basically paid for, but not very expensive.
Here is the link of video which gives me a lot help.