The fourth harmonic is the one you get from the string vibrating in quarters, at 4 Hz. This note is an octave higher than the second harmonic, and so is also called C. (The eighth harmonic will also play C, as will the sixteenth, and the thirty-second, and all the powers of two up to infinity.)
«Америка пожалеет». Что известно о новом верховном лидере Ирана и как к нему относятся в США?04:55
，更多细节参见新收录的资料
Jun Kokatsu and his，这一点在新收录的资料中也有详细论述
“These soldiers engaged in the most noble mission: protecting their fellow Americans and keeping our homeland secure,” Republican Sen. Joni Ernst of Iowa, a combat veteran, said earlier this week after the six were identified. “Our nation owes them an incredible debt of gratitude that can never be repaid.”。新收录的资料对此有专业解读