71.

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

The former sentence means "Because of the weight, Nicholas had to cut a piece of rope to untie the skydive at the end of the skydive", and the latter sentence means "he proved that Leonardo's design can reduce the speed of the skydiver." The front means that although cut himself free and deploy But parachute still has the function of slow descent, so the front and back are turning points, and A is correct.