1. Cut long rice cake into 4-5 cm pieces.

(How do you read '4-5 cm'?)

1-1. four to five centimeter
1-2. four and five centimeter
1-3 four or five centimeter
1-4 from four to five centimeter

(Which one is right? Do we have to read 'centimeters'?)

I'd read that like 1-1. And yes, you need to read the word "centimeters" in the sentence. Otherwise, you would say to cut it into 4 to 5 pieces!! There's a big difference!

To read '4-5 cm', the correct way is option 1-1: "four to five centimeters." In this case, the numbers '4' and '5' represent a range, indicating that the rice cake should be cut into pieces that are between 4 and 5 centimeters long.