Don’t forget to _______ the lights when you leave the classroom.

Look! There is a big river. Let’s swim in it!—No, I think it’s _________ dangerous.

Look at the young men. They _____ the bus.

Eight hundred and eighty-eight million, eight hundred and eighty-eight thousand, eight hundred and eighty-eight is _________.

Where’s your Mom, Xiao Hong? ––She ____ to music in her room.