Sudden blinking when something comes near your eyes is an example of kinesis
negative taxis
a reflective action
positive taxis

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

burning fossil fouls really decrease the carbon in the atmosphere so b