Mary _______ her mother with the housework, but she didn’t.
Of all the works Stevenson has written, Treasure Island is probably his _______ work.
The reason for their failure, you know, was _______ they didn’t get fully prepared for it.
John promised his parents he _______ not smoke again, and he has not smoked ever since.
My brother left home five years ago. I _______ nothing from him up to now.
The power to our region has been _______ by the heavy snow.