A case where one brings produce to the roof of a building to keep it away from insects, but it gets wet from dew, which makes the produce eligible to become impure. Plus, the ways in which intent (or lack thereof) has impact on the kashrut of one's shechitah (or one's sacrifice). Also, two very brief mishnayot: 1. If a non-Jew slaughters an animal in a way that would be kosher if it were done by a Jew, the animal is considered a "neveilah" and it imparts ritual impurity. 2. If one slaughters at night - or if a blind person slaughters - the shechitah is kosher, with some apparent difference of opinion whether that is considered kosher even in an ideal situation or only after the fact.