Ronald Amundsen is considered to be one of the greatest ________ in history because he was the first man to reach the South Pole (南极).
---Have a nice day! ---_____________.
---Is this key ________? --No, it isn’t. It’s ___________.
--Do you play sports? ---No, I watch them ____TV.
–Jim, let’s play ping-pang. ---______________________.
---Is that your friend? --- ______________.