its c!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Y, X, Z, W
Explanation:
You know W is the most recent because it features the nucleus in the middle and the electron cloud which was shown in models after the others.
Answer:
C.
Measure the wear on his treads before and after riding a certain number of laps.
C. Their strengths are added
