Used as an example, it leads to examples that introduce common concepts, and the scope of use is more free than that of. It can appear at the beginning or end of a sentence, and sometimes it can be inserted into a sentence as an independent language without affecting the grammatical relationship of other parts of the sentence.

For example, the encryption operation (such as decryption or signature) in a given period only involves the relevant temporary secret key, without further access to the helper.

Similarly, giving examples (for example) refers to giving a few examples in general, not all examples, including "and so on". If you add etc. Or so on, it is redundant.

This sentence that appears in the paper is inappropriate: the writing instructor pays attention to some complex skills that need a lot of practice (such as organization, clear expression, logical thinking, etc.). What is correct is, for example, organization, clear expression and logical thinking.