As we all know, tigers are in danger of dying out.
The villagers were warned ______ the water from the river polluted by the chemical works..
Last Sunday, Ms. Green went to the Beauty Salon, ______ hairdressing and dated with Mr. Right.
______ is going to the north of Alaska to take another advantage there.
They ______ to escape from prison last month, and now the police are still tracking them down.
It was at the entrance ______ we stood chatting ______ the accident happened.