-----Who has made a mess in my room? -----Who else it but your naughty son?
Mr. White will come to the party on Sunday, _______ he promised to every one of us.
Mary has recently got engaged ________ a foreign teacher, who has been engaged ________ education research for years.
Time ________ quickly. Three years passed before we knew it.
Mr. Smith is busy these days ________ a new book on how to develop a child’s reading skill.
It makes no ________ to me what she says. I won’t care.