Rings like this can form as an aircraft traveling low over the water nears the speed of sound.
当飞机在水面上以接近音速的速度飞行时就有可能产生这样的圆环。
2
While many aircraft designs often boast a low stall speed, many of these same designs have minimal control effectiveness at these lower speeds.
虽然许多飞机设计往往拥有低失速速度，设计许多这些同样具有这些低效益的速度，最低程度的控制。
3
The F-35C, designed for the US Navy, features larger wings to carry more fuel and provide better low-speed landing approach characteristics to an aircraft carrier.
F - 35c是专为美国海军设计的，采用了更大的机翼以携带更多的燃油并保证在航空母舰上更好的低速降落进场特性。