The hard, solid rocks, whose composition or texture has been changed by heat or pressure in the Earth are called____________?
A. Sedimentary rocks
B. Metamorphic rocks
C. Igneous rocks
D. All of the above
One Astronomical unit is equal to how much Km in whole numbers?
A. 160 million km
B. 140 million km
C. 150 million km
D. 130 million km
Approximate age of milky-way is ________?
A. 16.5 billion years
B. 15.5 billion years
C. 13.5 billion years
D. 14.5 billion years
Approximate age of earth is ________?
A. 4.14 billion years
B. 4.64 billion years
C. 4.54 billion years
D. 4.34 billion years
Approximate age of moon is _________?
A. 4.51 billion years
B. 4.55 billion years
C. 4.53 billion years
D. 4.57 billion years
Approximate age of sun is _________?
A. 4.4 billion years
B. 4.5 billion years
C. 4.6 billion years
D. 4.7 billion years
Which gas was discovered on the sun about 151 years ago during total solar eclipse?
A. Hydrogen
B. Helium
C. Nitrogen
D. Flourine
In which layer of atmosphere does commercial aircrafts usually fly?
A. Stratosphere
B. Troposphere
C. Mesosphere
D. Thermosphere