I don’t know how to do this

If a planet rotates 360 degrees during a 24 hour time period, what does that tell us about the planet? a. the middle of the planet is in darkness b. the seasons on the planet vary every day. c. the planet runs on a 12-hour time clock. d. the temperature on the planet varies daily.

The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle what is the common name for the group to which this organism belong

How many mmols of tris-hcl are there in 100 ml of a 100 mm tris-hcl buffer solution at ph 8.1? note that the 100 mm refers to the sum of tris and tris-hcl concentrations?