Which of the following produces 50 - 80 percent of oxygen on Earth?

• Forest

• Ocean

Which of the following is used in pencils?

• Graphite

• Charcoal

What is the symbol for Tungsten

• W

• T

Force is needed in order for an object to have motion?

• Yes

• No

In a free fall, the acceleration of a falling object is ___________.

• 9.81 m/s^2

• -9.81 m/s^2

The number 6.25X10^11 has how many zeroes?

• 11

• 9

If the weight of 75kg man on the moon is 125.25 N, what will be his mass on Earth?

• 75 kg

• 735.75 kg

Plants synthesis protein from ____________.

• Sugar

• Amino Acids

In a slab pull theory about Earth mechanics, what is the main driving force for the tectonic plates' motion?

• Gravity

• Heat

85% of the sun's energy came from the reaction of two atoms of what element?

• Helium

• Hydrogen