[填空题]
How fast is an objectfh w*z;ylo0ad3o+s3 db3-b*snfyw. r moving on lany +yt+o/ux6s 2s8vgj id if its speed at 20 $^{\circ} $C is Mach 0.33? m/s
(b) A high-flying jet cruising at 3000 km/h displays a Mach number of 3.2 on a screen. What is the speed of sound at that altitude? m/s