After a series of researches, they finally ___ that the pollution was the leading factor contributing to the death of the creatures in the river.
In such dry weather, the flowers will have to be watered if they ____________
It is the protection for the trees___________ really matters, rather than how many trees are planted.
We can’t go on with the experiment because the computer_________.
You can’t see the___________ now for they are having a meeting at the moment.
The two sides have finally___________, though some small differences still exist.