Many countries are increasing their use of natural gas, wind and other forms of _______.
.Not one in one hundred children exposed to the disease ______ likely to develop it.
Robert is said ______ abroad,but l don't know what country he studied in.
The purpose of new technologies is to make life easier,______it more difficult.
I've worked with children before,so I know what ______ in my new job.
Having a trip abroad is certainly good for the old couple,but ______whether they will enjoy it.