In the same circuit, the current in a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor. This is Ohm's law.

From the derivation of Ohm's law I=U/R, R=U/I or U=IR, we cannot say that the resistance of a conductor is proportional to the voltage across it and inversely proportional to the current passing through it, because the resistance of a conductor is a property of itself, which depends on the length, cross-sectional area, material, temperature, and humidity (humidity is not involved in the second year of elementary school). Even if there is no voltage across it and no current passes through it, its resistance is a constant. (This constant can be considered constant in general, because for photoresistors and thermistors, the resistance value is uncertain. For some conductors, superconductivity still exists at very low temperatures, which will affect the resistance value and must be considered.)