First, if the original file is not encrypted, you can generally copy the text, while the text in the form of pictures should be copied into pictures (or images).

Second, if it is encrypted, even the text may not be copied. At this time, you need to use conversion software to convert the text in PDF into WORD, and you can use image processing software (such as Adobe? Photoshop, Adobe Acrobat) to open the copy, but it is often impossible to copy with mathematical formulas, and you need to re-enter the formula through screenshots, pictures or manually.

Thirdly, for the words in PDF with mathematical formulas, even if we copy them, some symbols and formats will change greatly. At this time, you can only use mathtype to re-enter editing.

4. It should be noted that when the text in PDF is converted into WORD by conversion software, there will be errors, typos, shifts and other phenomena, which need to be carefully checked, checked and corrected.