Which statement about the respiratory electron transport chain is true?
a. electrons are received from nadh only.
b. the terminal electron acceptor is usually h2o.
c. most of the respiratory proteins are in the cytosol.
d. energy must be added to move electrons from one electron carrier to the next.
e. electrons are passed from donor to recipient carrier molecules in a series of oxidation–reduction reactions.

The answers are letter D and E . The two true statements are letters D and E

Explanation:

The true statements are: Electrons are passed from donor to recipient carrier molecules in a series of oxidation–reduction reactions, and Energy must be added to move electrons from one electron carrier to the next.

Letter A is false, because electrons are received from NADH and FADH2

Letter B is false, because the terminal electron acceptor is usually O2

Letter C is false, because most of the enzymes are part of the inner mitochondrial membrane.

B

Explanation:

Input force - the force a man apply on the inclined plain. It is less than the force the man should apply if he would just push the ball up.

Distance = hypotenuse becomes longer, that vertical distance (vertical leg).