With the Internet widely used, a(an)___change has taken place in the way people communicate with one another.
The door opened and in________.
You can take anything from the shelf and read,but please ________ the books when you've finished with them.
—You've made great progress in your studies of English,haven't you?—Yes,but much________.
Tom tried to escape from the burning building.________,he was hit by a piece of burning wood and was killed.
________is believed that the island can be a paradise(天堂)when people live________.