First off do you mean the game tetris? If so here is the answer:
Tetra is a prefix which means “four” and is used when forming compound words. In tetris, we use pieces (called tetrominos), which are formed by combining 4 small blocks (called minos). There are 7 possible types of tetrominos named after the letters that they resemble: I, O, L, J, T, S, and Z.
Answer: Caused to be a certain nature
Explanation:
If you replace the word “rendered” with “caused to be” the statement still makes sense. A good rephrasing would be:
The sad cries of the many slaves, horrible yesterday, are made worse by the joyous shouts that they hear.