How do musical instruments vary pitch?

by changing the frequency of standing waves

by increasing the amplitude of standing waves

by interrupting sound waves

by changing the wavelength of standing waves

Chameleons catch insects with their tongues, which they can rapidly extend to great lengths. in a typical strike, the chameleon's tongue accelerates at a remarkable 220 m/s2 for 20 ms, then travels at constant speed for another 30 ms.