1. It is book. (Correct)(Incorrect)
It is a book. (Correct)
2. I bought interesting book. (Correct)(Incorrect)
I bought an interesting book. (Correct)
3. This is book that you wanted. (Correct)(Incorrect)
This is the book that you wanted. (Correct)
4. I like to read books. (Correct)(Incorrect)
I like to read books. (Correct)
5. Do you go to work by bus? (Correct)(Incorrect)
Do you go to work by bus? (Correct)
6. Moscow is largest city in Russia. (Correct)(Incorrect)
Moscow is the largest city in Russia. (Correct)
7. He is engineer at a small company. (Correct)(Incorrect)
He is an engineer at a small company. (Correct)
8. Do you have computer? (Correct)(Incorrect)
Do you have a computer? (Correct)
9. He wrote letter to his friend in Canada. (Correct)(Incorrect)
He wrote a letter to his friend in Canada. (Correct)
10. Open door, please. (Correct)(Incorrect)
Open the door, please. (Correct)