Answer:
yes friction is needed hope this helps might of been to long tho
Answer:
valves
The heart has four valves - one for each chamber of the heart. The valves keep blood moving through the heart in the right direction.
Answer:
+1 ion
Explanation:
Alkali metals are metals that are found in Group I of the periodic table. Their electronic configuration is such that their valence shell in grounds state is always holding only one electron which they always lose when reacting with non-metals. A loss in an electron makes the atom electrically imbalanced and hence becoming a +1 ion.
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected.
I hope that this answer helps you