Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: The electron cloud of a helium atom contains two electrons, which can normally be expected to be equally distributed spatially around the nucleus. However, at any given moment the electron distribution may be uneven, resulting in an instantaneous dipole. This weak and temporary dipole subsequently influences neighboring helium atoms through electrostatic attraction and repulsion. It induces a dipole on nearby helium atoms (see Figure below ). Answer: an instantaneous dipole

Ex Output:
A weak and temporary dipole that influences nearby atoms through electrostatic attraction and repulsion is known as what?

Ex Input:
Passage: You can tell that this sponge is saturated with water because when it is squeezed, the water pours out. When something is saturated with water, it already holds as much water as possible. Compounds called hydrocarbons, which contain only carbon and hydrogen, can also be saturated, but not with water. Answer: hydrocarbons

Ex Output:
What compounds contain only carbon and hydrogen?

Ex Input:
Passage: Fish have a circulatory system with a two-chambered heart. Their digestive system is complete and includes several organs and glands. Jawed fish use their jaws and teeth to grind up food before passing it to the rest of the digestive tract. This allows them to consume larger prey. Answer: heart

Ex Output:
Fish have a circulatory system with a two-chambered what?