Questions

A cold or flu illness.

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

Photosynthesis can be represented using a chemical equation.

The overall balanced equation is

              $$\begin{gathered} 6CO2 + 6H2O →Sunlight C6H12O6 + 6O2 \\ Source of Carbon & Oxygen + \\ Source of Electrons & Hydrogen + \\ Energy that drives Photosynthesis ----> \\ Sugar + Gas produced by splitting water. \end{gathered}$$

Where 

CO2 = carbon dioxide 

H2O = water

C6H12O6 = glucose 

O2 = oxygen.

Distributed systems work in a network. They can share the network resources, communicate with each other.

There are approximately 6 trillion miles in a light-year, so the distance we need to go is 6 trillion miles / light-year times. 4 light-years is equal to 24 trillion miles. So, this whole would take 1.2 billion hours. There are 24 hours a day and 365.25 days per year, so this time in years is 137 thousand years.

Dull means not sharp, not shining, not bright, ...

Hence, the given words are all that means the opposite of dull.