The man and the horse _____ fell into the river were drowned.

　 A. Which 　 B. who C. that 　 D. of which

 The Science Museum, ________ we visited during a recent trip to Britain，is one of London’s tourist attractions.

A. which　　　B. what　　　C. that　　　D. where

The man and the horse _____ fell into the river were drowned.

　 A. Which 　 B. who  C. that 　 D. of which

Lucy and Sam made an appointment of an interview on Sunday afternoon,________ they would be free.?

A.which　      B.when　       C.then　        D.where ?

Along with the letter was his promise ______ he would visit me this coming Christmas.

A.which　　　　　　 B.that　　　　　 C.what　　　　　 D.whether