A simile can be found when using "like" or "as" between two things. Example: I'm as happy as a clown.
Your question would be a metaphor. Both things are being compared to a science expieriment, probably meaning that they need to have an outcome, but it isn't known for sure if it will be a good or bad outcome.
Things like this can be taken many ways, so if you think something else, I'm sure it would work as well.
Last one “He often gets sick”
The Duvitch family moves into the town I believe.
The prepositional phrase is "up the school steps"
The word "up" is the preposition in the sentence.
Hope that helped! :)
