Sugar(glucose) and oxygen.
Option C would be correct. The organ system can plays many parts at one time. Also, it is the only system listed.
Hope this helps!
A light-year is how astronomers measure distance in space, hope this helps ^^
The horsehoe crab because it was one of the first animals to ever live on earth
Viruses reproduce by inserting their genetic code into the genetic code of a cell, from there, an active virus will copy itself over and over until that cell bursts, where the new viruses can repeat the process. Another type of virus inserts itself into the genetic code, but does not actively reproduce. It sits and waits for the cell to reproduce for it, by splitting in the way cells do.
