I’m not sure ___ I can learn at present; but I’m sure it will be something ___ I might use in the future.
His father disappeared, ________ two children and never _______ from again.
Does the way you thought of ________ the water clean make any sense?
In order not to be disturbed, I spend three days _______ in my study.
Although he didn’t expect _______ me here, he advised _______ to the nearest restaurant.
They ’ll have other meetings like this in the weeks ________.