16. ---The farmer president was caught at last. ---Really? Where _ himself?
We live in ____ neighbourhood of the school and go to school on ____ foot.
There are lots of plastic bags ____ in the river, ____ it very dirty.
--- Would you mind if I used your bike? --- ____.
The president spoke at the business meeting for nearly an hour without ____ his notes.
David worked hard at his lessons ____ he gained high grades in the exams.