1. in which of the following sentences is the word its used correctly?
a. the monster reared its head at the tourists.
b. the problem with the lawn mower is that its old.
c. when trying to catch fish, its important to be patient.
d. its easy to learn to play the guitar, if you're willing to practice.

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.