An is performed by stitching together blood vessels.
this is medical terminology not chemistry, sorry.

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)

Iwould have to say

Mv^2 is a conserved quantity so v goes as sqrt(1/m) heavier is slower 64/4 = 16 sqrt(16) = 4