Ques: Q: What is the most common cause of lung cancer? Choices: - coal smoke exposure - restaurant smoke exposure - tree smoke exposure - tobacco smoke exposure A:
Ans: tobacco smoke exposure

Ques: Q: Density and pressure of air decreases with what? Choices: - temperature - humidity - horizontal distance - altitude A:
Ans: altitude

Ques: Q: What type of hydrocarbons contain at least one double or triple bond between carbon atoms? Choices: - ionic - catalytic - saturated - unsaturated A:
Ans: unsaturated

Ques: Q: By impacting plant species and the animals they support, destruction of habitat threatens what event? Choices: - overpopulation - depletion - mutation - extinction A:
Ans:
extinction