SPM 2013 SEJARAH KERTAS 3 Oktober. Tema Umum : Malaysia dan Kerjasama Antarabangsa
Did you know that ? Human ear can hear sound in the frequency range of 20 – 20,000 Hertz and are most sensitive to (able to discern at lowest intensity) frequencies between 2,000 and 5,000 Hertz while cats can detect frequency from 55 up to 79,000 Hertz. Dog’s range of hearing is usually around 40 to 60,000 Hertz.
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