8. He was so deep in thought, thinking of the problem ______ he knocked into the tree without noticing it.
In the past few years, sea ice ____ in the Arctic as a result of global warming.
Peter told us the work would be finished by next month, _____ personally I doubt very much.
By the time our teacher arrives tomorrow,all the work _____,with which he will be satisfied.
We’re running out _____________ fuel.
There’s no doubt2013 will bring more change when the world economy is still unclear.