A: Air masses move and meet.
(d) option is right answer
When we talk about that the sun rises and sets, an individual on the surface of the earth who is motionless or stationary is the spectator or observer. The observer may perhaps be on the moon to see that the sun does not travel all over Earth every 24 hours.
The one that accurately describes the products of a reaction is : B. new substances that are present at the end of a reaction
For example the process of photosynthesis transform CO2 and other nutrients into O2 and H2O
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