he past decades, sea ice _______ in the Arcticas a result of global warming.

The Internet is really ______ to us. We can easily find the information we need.

What about your journey to Mount Hua?— Everything was wonderful except that the car we rented________on the way back. [ ]

WHO, together with the medical workers in the different parts of the world, _____ trying to find a way to prevent the disease H1N1from _____. [ ]

We work together to achieve our common purpose: ________ world that is safer, cleaner and healthier than ________ one we are living in.