单选题：Only when he met the girl his aunt introduced to him ____ th..

Little __________ that we were watching his every move, so he seemed to be going his own way in this business. A．he realizedB．he didn’t realizeC．didn’t he realizeD．did he realize

If _____ carefully, the experiment will be successful.A．doB．doesC．doneD．doing

– Who should be responsible for the accident? – The boss, not the workers. They just carried out the order _____.A．as toldB．as are toldC．as tellingD．as they told

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 realizeD．I realize

No sooner____ on my comfortable bed______ my telephone rang.A．had I lain, thanB．I had lain, thanC．had I lain, whenD．did I lain , when