We were swimming in the lake _______ suddenly the storm started.

Did you call to book a ticket for the concert ?—Not yet, but I _______ .

What time do we have to be at the gate of the museum? — ______ the visitors begin to check in[ ]

On the contrary, I think it is Truman, ________ you, ________ to blame.

Friends should ______happiness and sorrow _____each other.