This is______difficult problem that few students can work it out.

He foundvery interesting to ride a horse on the farm.

What time ___________ we ___________ tomorrow? —At six in the morning．

Excuse me. I want to buy some stamps. Where can I find a post office?—I know _______ is not far from here. You can easily find _______.

The old lady isseriously ill we can’t tell her about the death of his son.