IV

1. were watching

2. haven't been cleaned

3. Are they practising

4. to change

V

1. misunderstood

2. inventor

3. famous

4. gradually

VI

1. A of

be full of : đầy

2. B events

3. C experience

4. D where

VII

1. The shortage of clean water is one of the most urgent environmental problems 

2. 1300

3. Massive volumes of industrial effluent which pour into the lake every day

4. No, they don't

VIII

1. they didn't want to send their son to a university in the USA

2. was designed by that well-known architect last year

3. is less hard-working than Tom

4. you follow your teacher's advice, you'll fail the final test

IV.

1 were watching

2 haven't been cleaned

3 are they practising

4 to change

V.

1 misunderstood

2 inventor

3 famous

4 gradually

VI.

1A 2B 3D 4D

VII.

1. They are urgent (câu hỏi này vô lý quá vì ko có dẫn chứng trong bài đọc)

2. There are 1,300.

3. Massive volumes of industrial effluent which pour into the lake everyday.

4. No, they aren't

VIII.

1 that they didn't want to send their son to a university in the USA.

2 was designed by that well-known architect last year.

3 is not as hard-working as Tom

4 you follow your teacher's advice, you'll fail the final test.