If it is the original data of the paper, it may be difficult to find out if it is adjusted, but it is also an academic misconduct, so don't do it easily.

Moreover, some data are not well modified, which is easy to be found by experienced reviewers, leading to punishment or withdrawal of manuscripts, which will affect the normal publication and graduation of your thesis.

Paper materials have been revised.

I don't know.

. The data in this paper are collected and processed by ourselves, and some dirty data or unusable data need to be deleted, adjusted and supplemented accordingly. Such data can't be seen by others at all, and it is a reasonable data adjustment. However, data adjusted for good results are not allowed.

You can't see it, because you need to see the modification of paper data in the process of calculation, so it is generally invisible.