Conservation efforts are working to some degree, but they're not (30) __________ the poaching, deforestation, and human encroachment that has devastated wild tiger habitats over the past 50 years.

During the past half-century, our species has embarked on a remarkable social experiment. For the first time in human history, great numbers of people - at all ages, in all places, of every political persuasion - have begun settling down as singletons. Until the second half of the last century, most of us married young and parted only at death. If death came early, we remarried quickly; if late, we moved in with family, or they with us. Now we marry later. We divorce, and stay single for years or decades.

The rise of living alone has produced significant social benefits, too. Young and middle-aged solos have helped to revitalise cities, because they are more likely to spend money, socialise and participate in public life. Contemporary solo dwellers in the US are primarily women: about 18 million, compared with 14 million men. The majority, more than 16 million, are middle-aged adults between the ages of 3S and 64. The elderly account for about 11 million of the total. Young adults between 18 and 34 number increased more than 5 million, compared with 500,000 in 1950, making them the fastest-growing segment of the solo-dwelling population.

Despite fears that living alone may be environmentally unsustainable, solos tend to live in apartments rather than in big houses, and in relatively green cities rather than in car-dependent suburbs. There's good reason to believe that people who live alone in cities consume less energy than if they coupled up and decamped to pursue a single-family home.

The best title for this passage could be                     .

Read the following passage and mark the letter A, B, C, or D to indicate the answer to each of the question.

Educating children at home as an alternative to formal education is an option chosen by families in many parts of the world. The homeschooling movement is popular in the United States, where close to one million Children are educated at home. In Canada, 1 percent of school-age children are homeschooled, and the idea also enjoys growing popularity in Australia, where 20,000 families homeschool their children. The movement is not limited to these countries. Homeschooling families can be found all over the world, from Japan to Taiwan to Argentina to South Africa.

Homeschooling is not a novel idea. In fact, the idea of sending children to spend most of their day away from home at a formal school is a relatively new custom. In the United States, for example, it was not until the latter part of the nineteenth century that state governments began making school attendance compulsory. Before that, the concept of a formal education was not so widespread. Children learned the skills they would need for adult life at home from tutors or their parents, through formal instruction or by working side by side with the adults of the family.

In the modern developed world, where the vast majority of children attend school, families choose homeschooling for a variety of reasons. For people who live in remote areas, such as the Australian outback or the Alaskan Wilderness, homeschooling may be their only option. Children who have exceptional talents in the arts or other areas may be homeschooled so that they have more time to devote to their special interests. Much of the homeschooling movement is made up of families who, for various reasons, are dissatisfied with the schools available to them. They may have a differing educational philosophy, they may be concerned about the safety of the school environment, or they may feel that the local schools cannot adequately address their children's educational needs. Although most families continue to choose a traditional classroom education for their children, homeschooling as an alternative educational option is becoming more popular.

Which of the following could be the main idea of the passage?

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

There has not been a great response to the sale, ________?