Answer:
One of Eight Planets : Earth
Spiral galaxy, One of the estimated billions of galaxies: Milky Way
Galaxy: Milky Way
Explanation:
According to the definition, appositive or apposition is a grammatical construction which represents similar noun phrases and nouns where one serves or defines the other one.
Here, the ultimate examples of apposition are mentioned in the given statement as Earth: One of Eight Planets, Milky Way: Spiral Galaxy and one of the estimated billions of galaxies: Milky Way.
With such kinds of words, it's easier to understand the noun or renames with a short definition written as a phrase.
Basic solutions are hydroxides therefore the answer is A ca(OH)2
Answer: 
Explanation:
Centripetal acceleration
is calculated by the following equation:
Where:
is the Earth's orbital speed
is the orbital radius

Answer:
1500 mph
Explanation:
Take east to be +x and north to be +y.
The x component of the velocity is:
vₓ = 889 cos 0° + 830 cos 59°
vₓ = 1316.5 mph
The y component of the velocity is:
vᵧ = 889 sin 0° + 830 sin 59°
vᵧ = 711.4 mph
The speed is found with Pythagorean theorem:
v² = vₓ² + vᵧ²
v² = (1316.5 mph)² + (711.4 mph)²
v = 1496 mph
Rounded to two significant figures, the jet's speed relative to the ground is 1500 mph.