They will give the award to_____devotes themselves to the protection of wildlife. 

The book was written in 1946,         the education system has witnessed great charges. 

He came here in the hope　　　he could learn about the cause of the accident. 

____is well-known to all, the great changes have taken place in China.

 Those children are wild. I feel sorry for _____ has to be their baby-sitter.