Answer:
3. crystal habit and cleavage.
Explanation:
Crystal habit is a distinctive characteristic which is shown in its general shape, crystallographic forms, how developed each form is.
Cleavage is the ability of a mineral to break in smooth planes parallel to zones of weak bonding. Cleavage in three directions at right angles (90o). Cubic cleavage. Cleavage in three directions not at right angles (120o and 60o).
Answer: A barrier should be created to overcome the atmosphere of the Venus, while launching spacecraft to Venus.
Explanation:
The atmosphere of Venus consists of 96.5% carbon dioxide, other composition includes nitrogen and other gases in trace amounts. The large amount of carbon dioxide in the atmosphere can extinguish the missile of the launcher of spacecraft thus it will become difficult in launch of spacecraft to the Venus.