______ most efficient way to understand thousands of new words is to gain ________ good knowledge of basic word formation.
. ______ I’m well again, I can go on with my work.
. The reason for his success is ______ he worked very hard.
. Can you tell me______the railway station?
. ______surprised me most was______ they had finished the work so quickly.
. The foreign guests, ____ were government officials, were warmly welcomed at the airport.