24. you’ d better I think _________him a hand when necessary .
30. He was told that it would be at least three more months ______ he could recover and return to work.
29. The field research will take Joan and Paul about five months; it will be a long time ______ we meet them again.
28.“When did he leave the classroom?” “He left _______ you turned back to write on the blackboard.”
27. “Shall Mary come and play computer games?” “No, _______ she has finished her homework.”
26. The visitor asked to have his picture taken _______ stood the famous tower.