what's diffrent between insist and persist?

[Bibos]

English Language Tests, Intermediate level

ESL/EFL Test #171 "Common subordinating conjunctions", question 10

......... they feel threatened, dogs sometimes display aggressive behavior.

(a) Until
(b) During
(c) When
(d) Before

English Language Tests, Intermediate level

ESL/EFL Test #171 "Common subordinating conjunctions", answer 10

When they feel threatened, dogs sometimes display aggressive behavior.

Correct answer: (c) When
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what's diffrent between insist and persist?
sometimes insist appear with on?
Thanks
Bibos

[Our Tort System]

If you persist IN doing something, you stubbornly keep doing it, despite obstacles.
If you insist ON doing something, you think that it is essential that something must be done.
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If it's not easy, don't do it!
That's how I got where I am.

[Saneta]

display aggressive behavior= show aggressive behavior?

thanks

[Beeesneees]

yes
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Cheers m' dears!