ACCORDING TO THE PASSAGE, HOW DID EDISON TEST HIS NEW INVENTION

5. - DE KIEM TRA HKII ANH 9
DE KIEM TRA HKII ANH 9
5. According to the passage, how did Edison test his new invention? A. He made improvements to the machine. B. He used a carbon transmitter. C. He read a children’s rhyme. D. He produced the audience