In a circuit, the wire must be
a. made of a conductor so the charges will flow.
b. made of a conductor so the charges will stop.
c. made of an insulator so the charges will flow.

Astudent poured a solution of bromothymol blue indicator into three test tubes. then he placed an aquatic plant in two of the test tubes, as shown below. he placed a stopper on each test tube and placed them all in the dark for 24 hours. bromothymol blue turns from blue to yellow in the presence of co2