In the following words, which underlined (划线的) letters have a different sound from the others?( )
brother
throat
them
The river is too wide for the swimmers _______________.
I am happy with my old friends today.
The policeman asked us _____him send the old man to the hospital.
()If there _____ no buying and selling of animals, there will be no killing in nature.
In summer milk will quickly go bad_____ it is put into a fridge.