The substance can be added to gasoline to ______ the speed of automobiles.
The general manager thought of______ problems before he made the final decision.
For a long time they walked without saying ____ word. Jim was the first to break ____ silence.
--- “I’ve never eaten a hamburger.” --- “_________ have I.”
In the exam, the _________ you are, __________ mistakes you will make.
. You don’t know ________ I want to see you again. It’s a year since I last saw you.