--- Did you return the book you borrowed from Tom?--- Yes, I gave it to him ______ I saw him.
-----What’s one of the major problems _____ the children living in remote mountainous areas?----- It’s poverty.
Doctors Without Boarders, ________ international organization, received ________ Nobel Prize for Peace in 1999 for its outstanding work .
It was several minutes ________ we realized what was happening—our dog was trapped in a newly-dug tunnel.
Luckily, I ________ before the deal turned bad, which saved me much money.
When you hear a fire alarm, don't rush________, you should keep calm.