The path to dreams may not be smooth and even at great cost, but ______ on to them.
Scientists still wonder ______ cloning will help or harm us and _____ it is leading us.
After the National Entrance Examination the students will have an anxious couple of weeks _____ for the results.
Then came the disturbing news ______ Dolly had become seriously ill.
Would it be ___ for you to pick me up at four o’clock and take me to the airport?
Students should be encouraged to use _____ Internet as _____ resource.