great scientist Yuan Longping is! He spent all his life on the research of rice.
What
What a
How
How a
How kind you are! You always do what you can ________ me.
---I have finished my homework already, Mum.--- When ________ you ________ it?
Lucy is ________ girl of the twin sisters.
---How did you work out the difficult chemistry problem?--- I worked it out by ________.
By the time we rushed to the hall, the party ________ for ten minutes.