Checking one's postal mailbox is generally reinforced on a schedule, because the mail only comes once per day at about the same time. choose the correct answer from the following choices
a) fixed-ratio
b) variable-ratio
c) fixed-interval
d) variable-interval

Ineed because i cannot find the answers anywhere

In 2016, two-year-old lane graves was wading in the lagoon of an orlando walt disney world resort and watching a family outdoor movie, when an alligator snatched the boy and disappeared. the resort had signs which read "no swimming, deep drop off" posted along the beach area where lane was taken, and his parents were a few feet away when the incident occurred. several hours later, lane's body was discovered about 15 yards from where he was taken by the gator. a disney employee said this was not the first time an alligator had been spotted in the lagoon beach area. if the graves family files a lawsuit against the resort, what theory would best support their claim?

How has our understanding of the first sentence of the declaration of independence changed over time?