Answer: Manholes are usually round, primarily because roundness is the best shape to resist the compression of the earth; covers are round because they are easier to manufacture than square or rectangular shapes, they are easier to move by rolling, and they can't fall into the opening.
Explanation:
The answer is the reaction ins a cold pack
The structure of tofacitinib with explicit carbon and hydrogen is the first attached picture.
The number of carbon atoms in tofacitinib are 16.
The molecular formula of tofacitinib is 
.
The structure of tofacitinib with all the filled hydrogen atoms is the second attached picture.
Answer:
the chemical equation of ethanol as fuel is
C2H5OH(l)+3 02(g)------2CO2(g)+3H2O(g)
the preparation process of ethanol from cassava is
cassava flour---liquification---saccharification---cooling---fermentation---distillation---ethanol
Answer:
It is important to collect all data first, or else your guesses could purely be the opposite of the right answer. If you make inferences of what might happen, your guesses may be purely fictional, and totally off-topic. During experiments, this step is important.
