How do Valentine's entrance and message affed the plot?
They foreshadow the eventual success of Duke
Orsino's pursuit of Olivia.
They make it clear that Duke Orsino's hunting trip
will succeed.
They suggest an obstacle to Duke Orsino's love for
Olivia.
They point to the obvious fact that Olivia has
betrayed Duke Orsino.

They suggest an obstacle to Duke Orsino's love for

Olivia.

martians or other types of aliens represent a unique fear as opposed to zombies. vampires and other types of monsters.   in most sci-fi stories, aliens come from other worlds and have different or more advanced technology.   abductions and experimentation on human bodies that involve these technologies, or the use of these technologies against human beings and the use of unknown "powers", are a type of fear that's different from that of other types of monsters.  

i think its c

independent