Answer:
F Anthracite (the hardest coal)
Explanation:
Coal is a sedimentary rock that is formed from plant materials. These plant materials must have been trapped and compacted in an environment where they are not able decay. Such an environment is a swamp.
The first grade of coal that forms initially in such an environment is called PEAT. Peat is soft coal that still contains some plant materials. It has a high moisture content and the amount of carbon is still quite low.
With increasing pressure and compaction, PEAT grades into LIGNITE which has more carbon atoms in it. Lignite is more combustible although it is quite soft too. Lignite grades into SUB-BITUMINOUS coal and then BITUMIOUS coal.
The highest grade of coal is ANTHRACITE which is a hard coal. It has very little moisture content and rich carbon percentage in it. Anthracite yields more energy compared to other forms of coal. Anthracite is basically coal that forms at the greastest pressure. Beyond this pressure, a metamorphic transformation occurs and the coals changes to graphite.
Based on increasing pressure:
PEAT< LIGNITE< BITUMINOUS COAL < ANTHRACITE
It is the source of the nation's petroleum deposits.
Answer:
The answer is C
Explanation:
I took the quiz and got it right
Shang Cities
During the Shang Dynasty, there were several large settlements, including Zhengzhou and Anyang, though these are not believed to be as densely urban as Mesopotamian settlements during the same time. Anyang became the capitol around 1300 B.C. under King Pan Geng and at the time was called Yin.
Answer: 
.
Explanation:
We are given that,
In △EFG,
To find: 
As we know that, angles opposite to the congruent sides of a triangle are congruent.
Thus, In △EFG
if and
then it implies 
Hence, we get .
