Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes (1) _______ ecosystems. If there is too (2) _______ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that feed on it may also die or move away. Some changes are good for ecosystems. Some pine forests need fires for he pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds (3) _______. Polluting the air, soil, and water can harm ecosystems. Building (4) _______ on rivers for electric power and irrigation can harm ecosystems around the rivers. Bulldozing wetlands and cutting down forests destroy ecosystems. Ecologists are working with companies and governments to find better ways of (5) _______ fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people without causing harm to ecosystems.

Điền vào ô trống 4

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.

After the social science lecture all students are invited to take part in a discussion of the issues which were risen in the talk

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

We arrived at airport. We realized our passports were still at home

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

As I have just had a tooth _______, I am not allowed to eat or drink anything for three hours

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

For lunch, I always haave something quick and easy: a sandwich, a salad, toast and the _______.

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

Something tells me that you _______ to a single word I _______ in the past ten minutes.

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.

The salary of a professor is higher than a secretary

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

We don’t seem to have any more of that book, Sir. It is out of _______ but we are getting a new delivery next Thursday if you would like to pop back then.