--- Derek, I owe you a thank – you for all your help. --- __________
Is this the reason _______ at the meeting for his carelessness in his work?
_______ puzzles me most is that I don’t know _______ the difference between those two lies.
In our classroom, the pupils work in groups, _______ helps them to learn to co-operate, to share and to develop leadership skill.
We agreed to accept _______ they thought was the best professor in the college.
I think Father would like to know _______ I’ve been up to so far, so I decide to send him a quick note.