The rule about subjects joined by 'and' is that there must be a subject-verb agreement. This means that if the subject is singular, then the verb must be also singular. On the other hand, if the subject is plural that means the verb must also be plural.
Answer:
Unrelenting and relentless
Explanation:
First let's define persistence. Then let's find the words that mean similar things to it.
Persistence - a quality that is someone continuing and trying to do something even though it is difficult or discouraged by others; not giving up
Basically, in simple terms, persistence means not giving up.
Unrelenting - not yielding in determination or strength; not giving up
nrelenting - not yielding in determination or strength; not giving upUnrelenting is a synonym to persistence.
relent - to stop or become less severe; to give up
Relentless - showing no stopping of intensity or pace; not giving up
elentless - showing no stopping of intensity or pace; not giving upRelentless is a synonym to persistence.
Yielding - giving way or stopping under pressure; to give up
Have a lovely rest of your day! :)