The old lady’s hand shook frequently. She explained to her doctor ______ this shaking had begun half a year before, and ______, only because of this, she had been forced to give up her job.

All __________ people on the earth should use the natural resources wisely, or they __________ by the nature sooner or later.

Why haven’t you returned the book yet -I ________to, but I forgot it.

The car has run 200 thousand kilometers and It needs _____ repairs. [ ]

Come on, Sam! I have _________________ to tell you.