Help please biology someone please help

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Which of these is an example of land degradation? a. containers designed to store pollutants leak. b. fertilizers provide too many nutrients to crops. c. garbage is buried so the land can be reclaimed later. d. a drought kills all the plants in an area, leaving bare land

What will happen if two of the base pairs of the stand of the dna are switched