to help them multiplye
nothing
multiplying
YES
the middle ages
The predominant staircase design in the Middle Ages was the spiral design for stairs. Spiral stairs were used from the medieval ages and are still used in many modern houses.
The hammer and sickle were used in the middle ages for a variety of different tasks. Both items were used to pound things into the ground and to cut grain.
they were used to grow apples.
Black magic was worse because it was used to put curses on people and/or to harm people. White magic was used to heal people and for good luck spells.
Mandrakes have been used since Biblical times in magic and alchemy. There is a link to an article below that explains more.
Maybe
Castles in the Middle Ages were used to keep out enemies.
See the question: What are some weapons used in the middle ages?
In the Middle Ages
people in the middle ages used letters or talking to face to face
because they used wood smoke as a deorderant in the middle ages
knights
YES
to entertain
Yes, polyphony was used during the Middle Ages. We do not have any real idea of when polyphony was introduced, but the earliest texts describing it date to the Early Middle Ages. By the end of the Middle Ages, it was highly developed. There is a link below to an article on polyphony, beginning at the section on its origins.