どんな厳しいことも容赦なく叩きつけてきたこれまでの流れから、その様子が異様なものであることを理解するのに、生徒たちもそう多くの時間を必要としなかった。
The sentence was from a light novel, and the story is about a teacher who came to the class to announce an unreasonable additional exam to her students.
叩きつけてきた from 叩きつける made me confused for its meaning:
From jisho.org
to throw violently against; to slam against; to strike; to slap something onto; to dash (e.g. to the floor)
to thrust at someone (e.g. a letter)
Then I found a much more relevant meaning for the translation from dictionary.goo.ne.jp:
激しい勢いで差し出す。 ( I was thinking maybe the word "present" here can also be translated as "announce".)
I wonder if my interpretation appropriate for this context.
Thank you for your kind guidance.