Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 31 to 35.

Dolphins are one of the most intelligent species on the planet, which makes them a very interesting animal to scientists. In their natural habitats, dolphins use various vocalization techniques. They whistle and squeak to recognize members of their pod, identify and protect their young, and call out warnings of danger. They also make clicking sounds used for echolocation to find food and obstacles in dark and murky waters.

Amazingly, the whistling sound that the bottlenose dolphin makes has been found to have a similar pattern to human language. They always make conversational sounds when they greet each other. If you listen to dolphins' squeaks and squeals, it will sound like they are having a conversation.

Dolphins usually use both sound and body language to communicate with each other. It is through gesture and body language, however, that most of their communication with humans comes. Dolphins can be trained to perform complicated tricks. This suggests they have a high level of intelligence and communication capacity. If they work for a long time with a trainer, they are able to recognize and understand human commands.

A lot of dolphin communication has been studied using dolphins in captive environments. These studies have been criticized because some marine biologists believe that dolphins living in aquariums or research centers cannot be considered "normal." Even so, most believe that studying dolphin communication in captivity is useful for beginning to understand the complexity of dolphin communication. After all, dolphins are one of the most intelligent animals. Their ability to communicate is impressive and worthy of study.

What would be the most suitable title for the passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

There are many theories of aging, but virtually all fall into the category of being hypotheses with a minimum of supporting evidence. One viewpoint is that aging occurs as the body's organ systems become less efficient. Thus failures in the immune system, hormonal system, and nervous system could all produce characteristics that we associate with aging. Following a different vein, many current researchers are looking for evidence at the cellular and sub cellular level.

It has been shown that cells such as human fibroblasts (generalized tissue cells) grown in culture divide only a limited number of times and then die. (Only cancer cells seem immortal in this respect). Fibroblast cells from an embryo divide more times than those taken from an adult. Thus some researchers believe that aging occurs at the cellular level and is part of the cell's genetic makeup. Any event that disturbs the cell's genetic machinery such as mutation, damaging chemicals in the cell's environment, or loss of genetic material, could cause cells to lose their ability to divide and thus bring on aging. Other theories of aging look at different processes. Chronological aging refers to the passage of time since birth and is usually measured in years. While chronological age can be useful in estimating the average status of a large group of people, it is a poor indicator of an individual person's status because there is a tremendous amount of variation from one individual to the next in regard to the rate at which biological age changes occur. For example, on the average, aging results in people losing much of their ability to perform strenuous activities, yet some elderly individuals are excellent marathon runners.

Another type of aging is cosmetic aging, which consists of changes in outward appearance with advancing age. This includes changes in the body and changes in other aspects of a person's appearance, such as the style of hair and clothing, the type of eyeglasses, and the use of a hearing aid. Like chronological aging, it is frequently used to estimate the degree to which other types of aging have occurred. However, it is an inaccurate indicator for either purpose because of variation among individuals and because a person's appearance is affected by many factors that are not part of aging, including illness, poor nutrition, and exposure to sunlight

 What is the best title for this passage?

Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete the following exchange.

Sarah and Kathy are talking about bad habits of children

-   Sarah: “Children under ten shouldn't stay up late to play computer games.”

-   Kathy: “         .”

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Mrs. Mai and  her friends from Vietnam plan to attend the festival now

                 A           B                                  C          D

Conan said to me, “If I were you, I would read different types of books in different ways.”