To help you answer this question, you can search a sample reaction in the internet for hydroboration-oxidation. Take a look at the attached picture. The sample reaction is shown at the top. We can deduce that the original compound must be an alkene. Following the pattern, compound a must be 2-methylbutene as shown in the picture.
Answer:
C Condensation of water vapor
Explanation:
One of the components of the atmosphere is water vapour. Water vapour is always present in air.
This water vapour may combine with particles of dust and smoke and condense around them to form clouds.
As more water vapour condenses and coalesces, the clouds become thicker and precipitation eventually follows.
A flight simulator that helps astronauts prepare for a shuttle launch is an example of a Scientific Model.
It's TISSUES.
CELLS, TISSUES, ORGANS, ORGAN SYSTEM, NEW ORGANISM