Four hundred and three babies are crying loudly. Do you know how to make them quiet in 41 seconds? There is an amazing new product on sale in prefix = st1 /Japanwhich does exactly this. It is an LP (a long-playing record) of sounds from inside a mother's body, which a hospital doctor recorded. In tests with the record she played the LP to 403 crying babies. After 41 seconds not one baby was crying and 161 of them were sleeping.  The record began as an experiment by Professor Hajime Minooka of the Nippon Medical University near Tokyo. He was looking for something natural that helped new-born babies go to sleep. The sound of the mothers' heart-beat and other body sounds are the things the babies heard inside their mothers. They feel safe and happy when they hear these sounds again. And they go to sleep.  Hospitals in Osaka and Tokyoare using the LP. 10, 000 young couples are using it too. Toshiba Music Company who makes and sells the records is very happy. One and a half million couples marry every year inJapan. Many will have babies, so the LP will definitely be a hit! Babies feel   _   when they hear these LP sounds.
the sounds to be their mothers' voices as if they were inside their mothers the music natural and soft themselves sleeping together with their mothers
Question: Four hundred and three babies are crying loudly. Do you know how to make them quiet in 41 seconds? There is an amazing new product on sale in prefix = st1 /Japanwhich does exactly this. It is an LP (a long-playing record) of sounds from inside a mother's body, which a hospital doctor recorded. In tests with the record she played the LP to 403 crying babies. After 41 seconds not one baby was crying and 161 of them were sleeping.  The record began as an experiment by Professor Hajime Minooka of the Nippon Medical University near Tokyo. He was looking for something natural that helped new-born babies go to sleep. The sound of the mothers' heart-beat and other body sounds are the things the babies heard inside their mothers. They feel safe and happy when they hear these sounds again. And they go to sleep.  Hospitals in Osaka and Tokyoare using the LP. 10, 000 young couples are using it too. Toshiba Music Company who makes and sells the records is very happy. One and a half million couples marry every year inJapan. Many will have babies, so the LP will definitely be a hit! Babies feel   _   when they hear these LP sounds.
A. the sounds to be their mothers' voices
B. as if they were inside their mothers
C. the music natural and soft
D. themselves sleeping together with their mothers
Answer: