Mrs Black isn’t in and I’ll have to ring ______. I would appreciate it if you ring _____ after 6 o'clock?  

While typing, Helen has a habit of stopping _____ to give her long and flowing hair a smooth.

____ most children nowadays are the only chidren, they tend to be more self-centered．

 Furniture and flooring usually come to mind when we think of ways to use bamboo. Not many of us, ________, think of bamboo clothing.

By the time the fire-fighters arrived, the fire had been put＿＿＿by the teachers and the students.