Two economic questions took up much of the group's time.

The patient is afraid to take too much of the doctor's time and doesn't ask questions.

Looking after an aging father took up much of her time.

But right now I've taken too much of your time.

May I take a few more minutes of your time and explain the reason?

And I promise to take very little of your time.

She was beginning to feel they were taking too much of the doctor's time.

"I thought we decided yesterday that it was better for me not to take too much of your time."

"Then we'll do our best not to take too much of your time."

It would be fair to answer them in written form as I do not want to take too much of your time.