For years scientists have been worried about the ______ of air pollution on the earth's natural conditions.
His success was because of ________ he had been working hard.
Although he didn’t expect _______ me here, he advised _______ to the nearest restaurant.
They ‘ll have other meetings like this in the weeks ________.
Not a single mistake _______ in the last test.
--- Jack will be admitted into a key university, according to his study. ---- ________, and ______.