Use the following rules:
- The sum of currents that enter and exit a node (junction) is always zero. So if you have 3 wires that connect, through one flows 2A, the other 3A, then the third must deliver 5A (taking the direction into account!)
- The sum of voltages across different components should always add up. So if you have a battery of 10V with two unknown resistors, and over one of the resistors is 4V, you know the other one has the remaining 6V.
- With resistors, V=I*R must hold.
With these basic rules you should get a long way!
The correct answer that would best complete the given statement above would be the word VIRUSES. Here is the complete statement. Viruses can only grow and multiply within the cells of another living thing, but they can remain active on a surface for several hours or days.
