— It _______ be Jack who is in the office.— No, it _______ be him. I saw him off at the airport half an hour ago.
I wish I ______ at my sister’s wedding last Tuesday, but I was on a business trip in New York then.
We need to get to the root of the problem______ we can solve it.
If you have any doubts about your health, you’d better______ your doctor at once.
Tom had tothe invitation to the party last weekend because he was too busy.
Despite the previous rounds of talks, no agreement______ so far by the two sides.