Extended stays in zero gravity are not healthy for human beings. thus, for the comfort of the astronauts, the station is rotated so that the astronauts feel there is what?

The four Science Regents exams (Earth Science, Living Environment, Chemistry, and Physics) also include separately-scheduled lab practicals.
In New York, students have the opportunity to take Regents Exams in grades 9-12 and, when appropriate, in grade eight.