Our teacher often tells us _______ our owncloth bags when shopping.

There was something wrong with the network，or the e-mail____ earlier.

In the bookshop, a reader asked the shopkeeper _______ A Brief History of Time (时间简史)was an interesting book.

What does your friend look like——_______________.

Someone is knocking at the door. Is it Ann- It_______ be her. She is giving a performance at the theatre now.