4 ____ a certain doubt among the students as to the necessity of the work.A There has had B They had C There existed D It existed
Danny left word with my secretary _______ he would call again in the afternoon.
Elephants have their own way to tell the shape of an object and _______ it is rough or smooth.
—Why does she always ask you for help? —There is no one else _______, is there?
Do you have any idea _______ is actually going on in the classroom?
Mary wrote an article on _______ the team had failed to win the game.