--What do you think of the 3-D printer?--It’s great although it still needs further ______.
Lin Fen _____a lot in the last few years.
You should the new words when you don’t know how to spell them.
--- ____ you ever _____to Yantai ? ---Yes, three times.
He’s never late for school, __________?
—You look worried. ________? — My grandpa is ill in hospital.