One third of the country ________ covered with trees and the majority of the citizens________black people.( 2011·湖南)
Many people have been ill from a strange disease these days,________ we’ve never heard of before.
—He_______ to the meeting. Have you informed him of it? —Sorry. I________to.
It is not enough only________ the rules of grammar if you want to learn English well.
He________ the person referred to be put in prison.
______you I owe a thousand apologies________ having doubted your ability.