Questions

Most known extrasolar planets most resemble to the planet Venus.

Photosynthesis process removes carbon dioxide from the atmosphere. Green plants remove carbon dioxide from the atmosphere by photosynthesis. 

The level of carbon dioxide in the atmosphere is maintained by several processes, including photosynthesis, respiration and combustion. 

There is no difference except for the fact that the first one gives a hint that the function fun() is probably in another source file.

A lower CPA may be accompanied by lower sales volume, reducing overall profit.

The unit which is used to measure weighted average atomic mass is Atomic Mass Unit (amu).

The amu or gram/mole can also be used for this measure.