Question

electric charges ammeters are devices that are used to measure electric current. They measure the rate that electric charges move through a *blank* called an ampere, or amp The unit of AMP
Fill in the blank

It's not conductor
It's not circuit

Answer 1

The unit of electric current measured by ammeters is called an **ampere**, or amp, and it measures the rate that electric charges move through a **conductor**. Since "conductor" is not suitable for your blank, an alternative term you could use is **path**.

So the completed sentence could read:

"They measure the rate that electric charges move through a **path** called an ampere, or amp."