Dogs have a very good ______ of smell and are often used to search for survivors in an earthquake.
It was some time _____ we realized the truth.
Having a trip abroad is certainly good for the old couple, but it remains _____ whether they will enjoy it.
—What does this sentence mean ? --- It seems to me that it ________.
Don’t leave matches or cigarettes on the table within ____ of little children.
Dad is used to smoking and drinking. There is no chance ____ I’m able to talk him into ______.