Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Ex Input:
The cardiovascular system in the human body consists of the heart, a network of blood vessels, and blood.

Ex Output:
Which system in the human body consists of the heart, a network of blood vessels, and blood?


Ex Input:
Ultrasound, a diagnostic technology, uses high-frequency vibrations transmitted into any tissue in contact with the transducer.

Ex Output:
What diagnostic technology uses high-frequency vibrations transmitted into any tissue in contact with the transducer?


Ex Input:
Scissors are compound machines.

Ex Output:

Are scissors simple or compound machines?