Answer:
manifest, latent
Explanation:
The manifest functions are the functions that have been caused by factors which are expected and observed while latent functions are caused by the factors which are unexpected and not deliberate.
Here, the students learned how social media influenced public opinion by "following" famous activists, academics, and politicians on Twitter which was the main function of this activity so, it is a manifest function.
Later, the students became friends after sharing tweets. This was not done deliberately and was an unintended consequence of the activity hence this was the latent function.