=>
I/
1. C âm câm còn lại /b/
2. B âm câm còn lại /b/
3. A âm câm còn lại /p/
4. D âm câm còn lại /b/
II/
1. B sự biến mất
2. A không thể
3. C worrying
4. C to V
5. A water pollution : ô nhiễm nước
III/
1. are caused
2. is made
3. was damaged
4. is included
5. were invited
6. has just been built
IV/
1. A lot of things must be done to clean up this river.
2. That course hasn't been taught by Professor River this semester.
3. My house isn't being painted because it is raining.
4. This paper is read by millions of people everyday.
5. Has the date of the meeting been changed?
6. I was taken to school everyday by my father when I was small.
