1. Not until I began to work ____ how much time I had wasted.
A. didn't I realize B. did I realize C. I didn't realize D. I realized
2. Only by practising a few hours every day ____ be able to master the language.
A. you can B. can you C. you will D. will you
3. If you don't go,neither ____.
A. shall I B. do I C. I do D. I shall
