My grandparents walk _____ twenty minutes a day.

How long is it _____ you visited your grandparents?

We have been dating _____ a long time.

That lady has been waiting for the bus _____ noon.

I studied for this test _____ three days straight.

My family has lived here _____ last March.

She has worked there _____ she finished college.

I have been calling you _____ half-an-hour.

Lisa and Jill have been at the library _____ a long time.

My teacher has been sick _____ last Monday.