The answer is B, look ahead and keep your eyes moving
A barcode's bars have
1. different thicknesses, so they each signify 1 or 2 nibbles.
2. the combinations of the thicknesses of those bars exceed the trillions. That's why manufacturers and stores never run out of SKU barcodes.
Am not sure about no.2 and no.4
But am going to answer
1.true
3.true
5.true
