Origins of the Domino Theory. In September 1945, the Vietnamese nationalist leader Ho Chi Minh proclaimed Vietnamâs independence from France, beginning a war that pitted Hoâs communist-led Viet Minh regime in Hanoi (North Vietnam) against a French-backed regime in Saigon (South Vietnam).
The human range is commonly given as 20 to 20,000 Hz, though there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal.
What is the normal respiratory frequency? Medical textbooks suggest that the normal respiratory rate for adults is only 12 breaths per minute at rest. Older textbooks often provide even smaller values (e.g., 8-10 breaths per minute). Most modern adults breathe much faster (about 15-20 breaths per minute) than their normal breathing frequency.