Q 46: A When they don't have the chance to do what they want.
Q 47: D Harmful conduct.
Q 48: B Many volunteers choose to hurt themselves rather than endure boredom
Q 49: C It may promote creative thinking.
Q 50: D Allow oneself some time to be bored.
Q 51: B Forests are fast shrinking in many developing countries.
Q 52: C Those that used to have the lowest forest coverage,
Q 53: A The governments' advocacy.
Q 54: C Their capability of improving air quality
Q 55: D Developed and developing countries are moving in opposite directions.