We still have a long way to go to solve all the problems _____________the Yangtze River.
They found themselves in front of a wooden house __________ with bamboos.
What do you mean, there are only ten tickets? There __________ be twelve.
She __________ the company's accounts, looking for evidence of fraud.
We forbid __________ here. Who has permitted you __________ here?
I __________ you __________ what you have achieved.