Tính: a) ( -17) + 23 + 77 + 17; b)  60 + 45 + ( -15) + ( -45); c) (-3) + (-185) + (-17) + 185; d) (-3) + (-4) + 66 + (-13)

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 28 to 34.

  Southern Thailand was hit Thursday by the most severe haze from forest fires in Indonesia, forcing all schools in a province to close and disrupting flights in a popular tourist area, officially said.

  The haze that has shrouded parts of Malaysia and Singapore for nearly two months reached hazardous levels in the southern Thai city of Songkhla, with the pollution index hitting a record-high reading of 365. A reading of 101-200 is unhealthy, 201-300 is very unhealthy and above 300 is hazardous.

  “This is a crisis,” said Halem Jemarican, head of the Southern Environment Office. He said the pollution index in southern Thailand has never exceeded 300 before. Halem said his office has worked with other authorities to have all schools in Songkhla province send students home and all outdoor sports stadiums to close temporarily. Warnings have been issued to vulnerable people such as children, the elderly and people with illnesses not to go out of their homes.

  “The wind speed is very low this year in the south, causing haze to stay in our skies longer,” Halem said by telephone.

  An airport official in Hat Yai, a popular tourist area, said three flights bound for Bangkok were delayed Thursday morning because of the haze. A flight from Bangkok to Hat Yai was diverted to Surat Thani on Wednesday evening. The official declined to be identified because of working rules.

  Local media reported that cloud seeding has been discussed as a way to dispel the haze in southern Thailand, which is hundreds of kilometers (miles) from the forest fires in Indonesia’s Sumatra island.

  Southern Thailand boasts tropical beaches popular among tourists in Surat Thani and Phuket, two of the seven provinces suffering from the haze.

What is the event reported in the news?

A. Southern Thailand was hit by the haze from Indonesia

B. People suffered because of the haze from Indonesia

C. The flights were disrupted by the haze on Thursday

D. The haze from Indonesia was the worst ever last year

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 35 to 42.

  Biological diversity has become widely recognized as a critical conservation issue only in the past two decades. The rapid destruction of the tropical rain forests, which are the ecosystems with the highest known species diversity on Earth, has awakened people to the importance and fragility of biological diversity. The high rate of species extinctions in these environments is jolting, but it is important to recognize the significance of biological diversity in all ecosystems. As the human population continues to expand, it will negatively affect one after another of Earth’s ecosystems. In terrestrial ecosystems and in fringe marine ecosystems (such as wetlands), the most common problem is habitat destruction. In most situations, the result is irreversible. Now humans are beginning to destroy marine ecosystems through other types of activities, such as disposal and runoff of poisonous waste; in less than two centuries, by significantly reducing the variety of species on Earth, they have irrevocably redirected the course of evolution.

  Certainly, there have been periods in Earth’s history when mass extinctions have occurred. The extinction of the dinosaurs was caused by some physical event, either climatic or cosmic. There have also been less dramatic extinctions, as when natural competition between species reached an extreme conclusion. Only 0.01 percent of the species that have lived on Earth have survived to the present, and it was largely chance that determined which species survived and which died out.

  However, nothing has ever equaled the magnitude and speed with which the human species is altering the physical and chemical world and demolishing the environment. In fact, there is wide agreement that it is the rate of change humans are inflicting, even more than the changes themselves, that will lead to biological devastation. Life on Earth has continually been in flux as slow physical and chemical changes have occurred on Earth, but life needs time to adapt-time for migration and genetic adaptation within existing species and time for the proliferation of new genetic material and new species that may be able to survive in new environments.

The word “jolting” is closest in meaning to _____.

A. illuminating 

B. unknown 

C. shocking 

D. predicted