I think JY misses a more explicit reason for A in q18. The passage states "no known peptide was able to bind to semiconductor materials..". This would imply that the later research on peptides was either on newly discovered naturally occurring peptides or synthetically grown. The next part of the passage says they respond to this by growing a billion peptides, which implies that they used the synthetic growing approach as opposed to natural discovery.
The placement of the word ‘known’ here is important.. If you take known and move it to say ‘no peptide was known to be able to…’ then it just means they weren’t aware of the ability. But the ‘known’ before ‘peptide’ rules out the existing natural ones.
With every PT I take, there seems to be one section that I struggle on, so I drill that section, take another PT, and do well on that section but now another one drops off that I used to do well on. Has anyone else experienced this? I feel like I am playing whack-a-mole
Good luck everyone! Channel your inner JY today