The first chemical explosive, Gunpowder, is a mixture of_____.

A. Sulfur, Charcoal and Nitrogen Oxide
B. Sulfur, Charcoal, and Potassium Nitrate
C. Sulfur and Charcoal
D. Charcoal and Potassium Nitrate

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Mitochondria contain their own supply of_____.

A. DNA

B. Amino acids
C. Vitamins
D. Oxygen

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______ are called the powerhouses of the cell.

A. Mitochondria
B. Vesicles
C. Lungs
D. Liver

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During photosynthesis, plants_____.

A. take in Carbon Dioxide
B. take in Oxygen
C. give off Carbon Dioxide
D. give off Oxygen (more…)

In night, when photosynthesis is stopped, plants_____.

A. take in Carbon Dioxide
B. take in Oxygen
C. give off Carbon Dioxide
D. give off Oxygen

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The device used to convert Alternate Current into Direct Current is called_____.

A. Anemometer
B. Battery
C. Galvanometer
D. Rectifier (more…)

The fourth state of matter is____.

A. Water
B. Salts
C. Vapours
D. Plasma (more…)

About 50% of the Earth’s crust, including the waters on the Earth and atmosphere, is_____.

A. Oxygen
B. Cabon Dioxide
C. Silicn
D. Clay

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Acid rain is mainly caused by emissions of _____ in the atmosphere.

A. Sulfur Dioxide and Potassium Nitrate
B. Sulfur and Charcoal
C. Nitrogen Oxide and Potassium Nitrate
D. Sulfur Dioxide and Nitrogen Oxide (more…)

In general, wind speed of 105–137 caused_____.

A. minor or no damage
B. considerable damage

C. severe damage
D. extreme damage

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