英语单选题1.______are changed into electrical signals.A.The sound

英语单选题
1.______are changed into electrical signals.
A.The sound's waves B.The sound waves
C.The sounds'waves D.The sounds waves
2.It was hard work,we enjoyed it ,________.
A.but B.even though C.though D.although
3.Please accept my congratulations ____your graduations.
a.to B.in C.on D.about
4.The children who do the best in the examination are not always _____with the best brains.
A.the children B.the one C.them D.the ones