25.If water becomes increasingly scarce in decades__________,water shortage will become a hot issue all over the world.
With a lot of difficult problems_________, they are working hard day and night!
--What’s the event like? --Several witnesses’ _______differ from the official version.
So much of interest ________ that most visitors run out of time before seeing it all.
The good thing about children is that they ________ very easily to new environments.
The lack of evidence and witness led to _______.