On his way to the airport, it ________ him all of a sudden that he had forgotten her birthday.

What were your parents doing when you phoned me last night?—They ________with my grandparents.

Students ought ______ the truth.

I wrote _____ my brother last Saturday, but I haven’t heard _____ him up to now. [ ]

We’ll have a hiking trip, but when shall we meet? —Let’s make it ______ half past eight ______ the morning of June 21. [ ]