(a) True
Metals are good conductors of electricity. They allow an electric current to flow through them easily. Hence, an electric current can flow through metals.
(b) False
Jute string is a bad conductor of electricity. If jute string is used to make an electric circuit, then the current will not flow through it. Hence, strings made of jute cannot be used to make circuits.
(c) False
Thermocol is a bad conductor of electricity. Hence, electric current cannot pass through it.