15000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 14)

In the 1960s, The Beatles were probably the most famous pop group in the whole world. Since then, there have been a great many groups that have achieved enormous fame, so it is perhaps difficult now to imagine how sensational The Beatles were at that time. They were four boys from the north of England and none of them had any training in music. They started by performing and recording songs by black Americans and they had some success with these songs. Then they started writing their own songs and that was when they became really popular. The Beatles changed pop music. They were the first pop group to achieve great success from songs they had written themselves. After that it became common for groups and singers to write their own songs. The Beatles did not have a long career. Their first hit record was in 1963 and they split up in 1970. They stopped doing live performances in 1966 because it had become too dangerous for them – their fans were so excited that they surrounded them and tried to take their clothes as souvenirs! However, today some of their songs remain as famous as they were when they first came out. Throughout the world many people can sing part of a Beatles song if you ask them.

Understanding India's Caste System

It has been said that life is what we make of it. In other words, if we work hard and focus on our goals, we can have great careers and enjoy high status is society. However, these opportunities don’t exist for everyone. In some places, the family you are born into will decide almost everything about your life. India’s caste system is an example of this.   

The caste system is a major part of the Hindu religion that has existed for thousands of years. It is a way of organizing and grouping people based on the occupation of the family. Castes will determine whom people can socialize with and their place in society. Originally, a person’s caste was supposed to be determined by their personality, but over time it has been linked to their job and family.

There are four classes, also known as varnas, in India’s caste system. The highest one is Brahmin. People in this class have jobs in education and religion. These are seen as extremely important functions for the society as they deal with the knowledge. The second highest level is the Kshatriya, or ruling class. People from this group can be soldiers, landowners, or have jobs in politics. The class beneath this is the Vaishya. These people often work in the commercial sector as merchants. The fourth class level is the Shudra. Shudras typically work as unskilled labourers doing factory or farm work, or they may also be employed as artists. 

There is another group, the Harijan, that is at the bottom and considered to be outside of the caste system. For many years, they were known as Untouchables, people from this caste held the most undesirable jobs in society, such as cleaning up garbage. Furthermore, they weren’t allowed to pray at public temples or drink water from the same wells as other classes. If someone from another caste came into contact with an Untouchable, they were considered dirty and would be expected to bathe vigorously to clean themselves. 

Although the caste system still exists in India, the government is taking steps to improve the living conditions and decrease unemployment rates for the Shudras and Harijan. This includes providing better health care, offering literacy programmes, and making sure that people from higher social classes do not exploit them. It seems unlikely that the caste system will disappear any time soon, but the overall conditions for those at the bottom do seem to be improving.

Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds – any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete for sunlight, nutrients, and water with useful plants. 

The global need for weed control had been answered mainly by the chemical industry. Its herbicides are effective and sometimes necessary, but some pose serious problems, particularly if misused. Toxic compounds threaten animal and public health when they accumulate in food plants, groundwater, and drinking water. They also harm workers who apply them.

In recent years, the chemical industry has introduced several herbicides that are more ecologically sound. Yet new chemicals alone cannot solve the world’s weed problems. Hence, scientists are exploring the innate weed-killing powers of living organisms, primarily insects and microorganisms. 

The biological agents now in use are environmentally benign and are harmless to humans. They can be chosen for their ability to attack selected targets and leave crops and other plants untouched. In contrast, some of the most effective chemicals kill virtually all the plants they come in contact with, sparing only those that are naturally resistant or have been genetically modified for resistance. Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. Chemicals typically must be used several times per growing season.