It is not socially __________ for parents to leave children unattended at that age.
Not only ______ polluted but ______ crowded.
The book I bought from the bookstore isn’t here. Who __________?
The official made the demand that the soldiers _____ at once ______ battlefront.
— I will come to attend your lecture at 10:00 tomorrow.— I’m sorry, by then my lecture will have ended and I _____ in my office.
The Internet in modern society has brought _______ great changes in our daily life.