Ⅰ)Mary made coffee________her guests werefinishing their meal.

This is the hotel _______last month.

I can’t fix my mind on my study, with the children ______ so noisily outside my window.

He offered to _____ her a hand as the suitcase was too heavy for her to carry.

The lecture was so complex that I simply couldn’t ______ at all. Could you explain it to me?