66. Why does the writer end up with question in Paragraph 1?

1. Very few of the overweights succeed in dieting.
2. He wants to probe into what really causes dieting failure.
3. The statistical figures provided by medical studies are unreliable.
4. So many reducing programs are unrealistic.

67. Can you tell the meaning of the word "svelte" from its context?

1. Slender.
2. Beautiful.
3. Energetic.
4. Ideal.

68. According to paragraph 3, dieting failure is caused by ____.

1. the dieter's former eating habits
2. an over-abundance of tempting foods
3. the dieter's strong desire for food
4. the strict and impracticable regime of diet

69. The scientific knowledge of dieting ____.

1. may put dieters at a loss what to do
2. helps in the battle against overweight
3. makes people fear no more of ice cream or dessert
4. makes known the ill effects of yo-yo dieting on dieters

70. In the last paragraph, the writer points out that ____.

1. diets may create a predisposition to mental disorders
2. changes in metabolism can be brought about by repeated dieting
3. people do not feel like eating anything while dieting
4. dieting may distort the body's hunger cues

(Reference keys.)