—Three buses went by without stopping while I___________ at the bus stop.
—Of course. You in the library at that time.
— I was doing my homework.
—Oh, I some cooking in the kitchen and didn't hear it.
—Oh, I some shopping at that time.
—Sorry, I ______the coronavirus vaccine （新冠疫苗）in the hospital at that time.
— Three buses went by without stopping while I ________ at the bus stop.
