<span>The oldest of those supercontinents is called Rodinia and was formed during Precambrian time some one billion years ago. Another Pangea-like supercontinent,
Pannotia, was assembled 600 million years ago, at the end of the
Precambrian. Present-day plate motions are bringing the continents
together once again.</span>
BF3 acts as a Lewis acid when it accepts the lone pair of electrons that NH3 donates.
Rock is a combination of two or more minerals, and it does not possess any specific chemical composition. It is present naturally in the environment. Some examples of rocks are limestone, granite, etc.,Limestone may contain minerals like calcite and aragonite. Each mineral has a specific chemical composition with a well defined crystalline structure.
Therefore, the correct option would be a. rock as rock is the naturally occurring solid mass made up of different types of minerals.
Answer:
B
Explanation:
Shows actual sacrifice in order to train and be the best.